SLXA swap information
06-22-2019
#1
SLXA swap information
I just finished my BMXA to JDM SLXA Stream transmission swap in my 2005 Honda Civic when my 243K mile BMXA transmission completely failed and left me on the side of the road. For those of you who don't know, I have a JDM D17A wiring harness and PCM from a Honda Stream RN1, which may have an effect on the outcome of the transmission swap.
I have had this transmission for about 2 years but I didn't install it until my transmission completely failed. Before I installed the replacement transmission, I took it apart to change the internal filter and case gaskets. I will make a writeup on how to change the internal filter soon for the people who are installing used transmissions.
The filter was surprisingly almost perfectly clean, but it was the old style small filter. The best way I can explain the difference is the filter that came out was a single filter, and the new filters are an updated design and are basically a much larger double filter with 2 filters in the housing. I have read that the early Civics (2001-2002 IIRC) used a single filter but the transmissions failed early because of it, so the later Civics used a double filter and had much less transmission problems. I'm far from a transmission expert though, so I may be wrong.
As for the actual swap, it wasn't too hard. I chose to take the sub frame down and remove/install the trans through the bottom of the car rather than pulling the engine and trans together, but how to swap a trans is beside the point of this thread.
The new trans installed just like a BMXA trans would have, nothing much to say about the install. All of the electrical connections and mounting points are identical. However, there are a couple of minor differences. The main difference is that the gear shifter inside the car doesn't line up perfectly after the swap, so when the trans is in D, the lever is half way between D and D3. I don't care though, and I might even be able to adjust the shift cable to make it line up.
The other difference is the range sensor. The BMXA and SLXA range sensors look the same, but they actually aren't. For the sake of experimenting I tried using the BMXA range sensor, but I was unable to adjust it to read correctly on the SLXA trans since the clicks are further apart with the SLXA transmission. My SLXA trans is a 5 click 6 position, but for some reason the BMXA trans is a 6 click 7 position even though the shifter only has 6 positions. However, I have read that some SLXA transmissions are only 4 click 5 position though, so I have no idea about those, if they even exist.
The other thing I noticed is that the gearing is different. The gearing is a bit shorter, which makes sense because it is geared to pull a heavy station wagon rather than a small sedan. I noticed that the car feels a little bit quicker off the line, and it also feels much quicker when I floor it getting onto the highway because 2nd gear is shorter. However, one possible disadvantage of this gearing is a little lower highway MPG because the cruising RPM is higher. 60 MPH with the old trans was around 2300 RPM, but with the new trans 60 MPH is about 2800 RPM. I will report back with my new MPG once I drive a bit more.
The exact gear ratios of an SLXA transmission are as follows:
1st: 2.722
2nd: 1.516
3rd: 1.078
4th: 0.711
Reverse: 1.954
Final drive ratio: 4.357
I do not get any transmission related trouble codes with my JDM PCM, but I have read that a US PCM will set a P0740 and/or a P0741 code with an SLXA trans, presumably because the PCM interprets the higher cruising RPM as the torque converter not locking up. However, from what I have read, the code does not affect the way the car drives, it just causes an engine light.
That is everything I can think of at the moment, but I will be sure to add more information if I think of it. Also, please comment if you have questions, comments, concerns, or feedback.
I have had this transmission for about 2 years but I didn't install it until my transmission completely failed. Before I installed the replacement transmission, I took it apart to change the internal filter and case gaskets. I will make a writeup on how to change the internal filter soon for the people who are installing used transmissions.
The filter was surprisingly almost perfectly clean, but it was the old style small filter. The best way I can explain the difference is the filter that came out was a single filter, and the new filters are an updated design and are basically a much larger double filter with 2 filters in the housing. I have read that the early Civics (2001-2002 IIRC) used a single filter but the transmissions failed early because of it, so the later Civics used a double filter and had much less transmission problems. I'm far from a transmission expert though, so I may be wrong.
As for the actual swap, it wasn't too hard. I chose to take the sub frame down and remove/install the trans through the bottom of the car rather than pulling the engine and trans together, but how to swap a trans is beside the point of this thread.
The new trans installed just like a BMXA trans would have, nothing much to say about the install. All of the electrical connections and mounting points are identical. However, there are a couple of minor differences. The main difference is that the gear shifter inside the car doesn't line up perfectly after the swap, so when the trans is in D, the lever is half way between D and D3. I don't care though, and I might even be able to adjust the shift cable to make it line up.
The other difference is the range sensor. The BMXA and SLXA range sensors look the same, but they actually aren't. For the sake of experimenting I tried using the BMXA range sensor, but I was unable to adjust it to read correctly on the SLXA trans since the clicks are further apart with the SLXA transmission. My SLXA trans is a 5 click 6 position, but for some reason the BMXA trans is a 6 click 7 position even though the shifter only has 6 positions. However, I have read that some SLXA transmissions are only 4 click 5 position though, so I have no idea about those, if they even exist.
The other thing I noticed is that the gearing is different. The gearing is a bit shorter, which makes sense because it is geared to pull a heavy station wagon rather than a small sedan. I noticed that the car feels a little bit quicker off the line, and it also feels much quicker when I floor it getting onto the highway because 2nd gear is shorter. However, one possible disadvantage of this gearing is a little lower highway MPG because the cruising RPM is higher. 60 MPH with the old trans was around 2300 RPM, but with the new trans 60 MPH is about 2800 RPM. I will report back with my new MPG once I drive a bit more.
The exact gear ratios of an SLXA transmission are as follows:
1st: 2.722
2nd: 1.516
3rd: 1.078
4th: 0.711
Reverse: 1.954
Final drive ratio: 4.357
I do not get any transmission related trouble codes with my JDM PCM, but I have read that a US PCM will set a P0740 and/or a P0741 code with an SLXA trans, presumably because the PCM interprets the higher cruising RPM as the torque converter not locking up. However, from what I have read, the code does not affect the way the car drives, it just causes an engine light.
That is everything I can think of at the moment, but I will be sure to add more information if I think of it. Also, please comment if you have questions, comments, concerns, or feedback.
12-06-2019
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Re: SLXA swap information
I bought my 2004 Civic VP coupé with an SLXA already in it, so I have no idea where it came from. I was told it was imported from Japan, but I'm kinda skeptical. Previous owner wasn't exactly informed, other family members had to speak up for her.
I'm curious as to what you mean about a 5 click, 6 position SLXA.
I haven't checked the range sensor itself, but inside it takes P, R, N, D, and then when it's in what should be D3 -which is as far as it goes- my D2 indicator lights up and then D starts flashing. If I shift it back to D, it still feels like it's in a lower gear... whether it's D3 or D2. So that's 5 positions I assume.
Shutting off the car and starting it up again fixes that.
I'm curious as to what you mean about a 5 click, 6 position SLXA.
I haven't checked the range sensor itself, but inside it takes P, R, N, D, and then when it's in what should be D3 -which is as far as it goes- my D2 indicator lights up and then D starts flashing. If I shift it back to D, it still feels like it's in a lower gear... whether it's D3 or D2. So that's 5 positions I assume.
Shutting off the car and starting it up again fixes that.
12-12-2019
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I just finished my BMXA to JDM SLXA Stream transmission swap in my 2005 Honda Civic when my 243K mile BMXA transmission completely failed and left me on the side of the road. For those of you who don't know, I have a JDM D17A wiring harness and PCM from a Honda Stream RN1, which may have an effect on the outcome of the transmission swap.
I have had this transmission for about 2 years but I didn't install it until my transmission completely failed. Before I installed the replacement transmission, I took it apart to change the internal filter and case gaskets. I will make a writeup on how to change the internal filter soon for the people who are installing used transmissions.
The filter was surprisingly almost perfectly clean, but it was the old style small filter. The best way I can explain the difference is the filter that came out was a single filter, and the new filters are an updated design and are basically a much larger double filter with 2 filters in the housing. I have read that the early Civics (2001-2002 IIRC) used a single filter but the transmissions failed early because of it, so the later Civics used a double filter and had much less transmission problems. I'm far from a transmission expert though, so I may be wrong.
As for the actual swap, it wasn't too hard. I chose to take the sub frame down and remove/install the trans through the bottom of the car rather than pulling the engine and trans together, but how to swap a trans is beside the point of this thread.
The new trans installed just like a BMXA trans would have, nothing much to say about the install. All of the electrical connections and mounting points are identical. However, there are a couple of minor differences. The main difference is that the gear shifter inside the car doesn't line up perfectly after the swap, so when the trans is in D, the lever is half way between D and D3. I don't care though, and I might even be able to adjust the shift cable to make it line up.
The other difference is the range sensor. The BMXA and SLXA range sensors look the same, but they actually aren't. For the sake of experimenting I tried using the BMXA range sensor, but I was unable to adjust it to read correctly on the SLXA trans since the clicks are further apart with the SLXA transmission. My SLXA trans is a 5 click 6 position, but for some reason the BMXA trans is a 6 click 7 position even though the shifter only has 6 positions. However, I have read that some SLXA transmissions are only 4 click 5 position though, so I have no idea about those, if they even exist.
The other thing I noticed is that the gearing is different. The gearing is a bit shorter, which makes sense because it is geared to pull a heavy station wagon rather than a small sedan. I noticed that the car feels a little bit quicker off the line, and it also feels much quicker when I floor it getting onto the highway because 2nd gear is shorter. However, one possible disadvantage of this gearing is a little lower highway MPG because the cruising RPM is higher. 60 MPH with the old trans was around 2300 RPM, but with the new trans 60 MPH is about 2800 RPM. I will report back with my new MPG once I drive a bit more.
The exact gear ratios of an SLXA transmission are as follows:
1st: 2.722
2nd: 1.516
3rd: 1.078
4th: 0.711
Reverse: 1.954
Final drive ratio: 4.357
I do not get any transmission related trouble codes with my JDM PCM, but I have read that a US PCM will set a P0740 and/or a P0741 code with an SLXA trans, presumably because the PCM interprets the higher cruising RPM as the torque converter not locking up. However, from what I have read, the code does not affect the way the car drives, it just causes an engine light.
That is everything I can think of at the moment, but I will be sure to add more information if I think of it. Also, please comment if you have questions, comments, concerns, or feedback.
I have had this transmission for about 2 years but I didn't install it until my transmission completely failed. Before I installed the replacement transmission, I took it apart to change the internal filter and case gaskets. I will make a writeup on how to change the internal filter soon for the people who are installing used transmissions.
The filter was surprisingly almost perfectly clean, but it was the old style small filter. The best way I can explain the difference is the filter that came out was a single filter, and the new filters are an updated design and are basically a much larger double filter with 2 filters in the housing. I have read that the early Civics (2001-2002 IIRC) used a single filter but the transmissions failed early because of it, so the later Civics used a double filter and had much less transmission problems. I'm far from a transmission expert though, so I may be wrong.
As for the actual swap, it wasn't too hard. I chose to take the sub frame down and remove/install the trans through the bottom of the car rather than pulling the engine and trans together, but how to swap a trans is beside the point of this thread.
The new trans installed just like a BMXA trans would have, nothing much to say about the install. All of the electrical connections and mounting points are identical. However, there are a couple of minor differences. The main difference is that the gear shifter inside the car doesn't line up perfectly after the swap, so when the trans is in D, the lever is half way between D and D3. I don't care though, and I might even be able to adjust the shift cable to make it line up.
The other difference is the range sensor. The BMXA and SLXA range sensors look the same, but they actually aren't. For the sake of experimenting I tried using the BMXA range sensor, but I was unable to adjust it to read correctly on the SLXA trans since the clicks are further apart with the SLXA transmission. My SLXA trans is a 5 click 6 position, but for some reason the BMXA trans is a 6 click 7 position even though the shifter only has 6 positions. However, I have read that some SLXA transmissions are only 4 click 5 position though, so I have no idea about those, if they even exist.
The other thing I noticed is that the gearing is different. The gearing is a bit shorter, which makes sense because it is geared to pull a heavy station wagon rather than a small sedan. I noticed that the car feels a little bit quicker off the line, and it also feels much quicker when I floor it getting onto the highway because 2nd gear is shorter. However, one possible disadvantage of this gearing is a little lower highway MPG because the cruising RPM is higher. 60 MPH with the old trans was around 2300 RPM, but with the new trans 60 MPH is about 2800 RPM. I will report back with my new MPG once I drive a bit more.
The exact gear ratios of an SLXA transmission are as follows:
1st: 2.722
2nd: 1.516
3rd: 1.078
4th: 0.711
Reverse: 1.954
Final drive ratio: 4.357
I do not get any transmission related trouble codes with my JDM PCM, but I have read that a US PCM will set a P0740 and/or a P0741 code with an SLXA trans, presumably because the PCM interprets the higher cruising RPM as the torque converter not locking up. However, from what I have read, the code does not affect the way the car drives, it just causes an engine light.
That is everything I can think of at the moment, but I will be sure to add more information if I think of it. Also, please comment if you have questions, comments, concerns, or feedback.
12-12-2019
#4
Re: SLXA swap information
Also, all of the Honda Stream PCMs that I have seen are for VTEC engines, so if yours doesn't have VTEC you would have to figure something else out, possibly a Civic ECU or something. Does your car have a VTEC engine? Also, what year is it? 01-03 has narrow band o2 sensor, 04-05 has wideband o2 sensor and the PCM's are not interchangeable.
12-12-2019
#5
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A USDM PCM will set a P0740 code with an SLXA trans, it is okay. Yes, getting a JDM PCM will eliminate the code since it is programmed to work with that trans, and yes it will communicate with a scanner. There are a couple of things to keep in mind though. Most JDM PCMs don't have immobilizers, only the ones with the last 3 digits of the part number starting with N do. This means it will start right up with no programming required.
Also, all of the Honda Stream PCMs that I have seen are for VTEC engines, so if yours doesn't have VTEC you would have to figure something else out, possibly a Civic ECU or something. Does your car have a VTEC engine? Also, what year is it? 01-03 has narrow band o2 sensor, 04-05 has wideband o2 sensor and the PCM's are not interchangeable.
Also, all of the Honda Stream PCMs that I have seen are for VTEC engines, so if yours doesn't have VTEC you would have to figure something else out, possibly a Civic ECU or something. Does your car have a VTEC engine? Also, what year is it? 01-03 has narrow band o2 sensor, 04-05 has wideband o2 sensor and the PCM's are not interchangeable.
12-12-2019
#6
Re: SLXA swap information
You will either need to get a JDM or EX harness and run a wire from the VTEC solenoid to the PCM pin for the VTEC solenoid, no need to worry about the pressure switch since the JDM engine doesn't use it. The bigger problem would be the downstream o2 sensor wiring. The Vtec engines use a downstream o2 sensor in the exhaust pipe instead of connecting to the under hood harness, so if you don't wire that you will be no better off than before since you will still have a code.
12-14-2019
#7
Re: SLXA swap information
Now that I have driven it a bit more with the SLXA transmission, I have a better idea of how gas mileage was affected. I usually get at least 26 MPG driving around town, usually even higher than that, which is somewhere around what I was getting with my old trans. I recently went on a road trip to North Carolina and I averaged 38 MPG going 70+ MPH most of the way with a best tank of 39.3 MPG, which is darn good IMO. I probably could have averaged 40+ MPG if I went slower.
12-14-2019
#9
Re: SLXA swap information
EDIT: I also converted to electric power steering (no more drag on the engine from the pump and belt), lightweight alloy wheels, and Nology non resistor spark plugs.
Last edited by D17VTECPOWER; 12-14-2019 at 05:05 PM. Reason: Added info
06-24-2023
#10
Re: SLXA swap information
I bought my 2004 Civic VP coupé with an SLXA already in it, so I have no idea where it came from. I was told it was imported from Japan, but I'm kinda skeptical. Previous owner wasn't exactly informed, other family members had to speak up for her.
I'm curious as to what you mean about a 5 click, 6 position SLXA.
I haven't checked the range sensor itself, but inside it takes P, R, N, D, and then when it's in what should be D3 -which is as far as it goes- my D2 indicator lights up and then D starts flashing. If I shift it back to D, it still feels like it's in a lower gear... whether it's D3 or D2. So that's 5 positions I assume.
Shutting off the car and starting it up again fixes that.
I'm curious as to what you mean about a 5 click, 6 position SLXA.
I haven't checked the range sensor itself, but inside it takes P, R, N, D, and then when it's in what should be D3 -which is as far as it goes- my D2 indicator lights up and then D starts flashing. If I shift it back to D, it still feels like it's in a lower gear... whether it's D3 or D2. So that's 5 positions I assume.
Shutting off the car and starting it up again fixes that.
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D17VTECPOWER (06-24-2023)
07-10-2023
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I swapped out a bummed BMXA for a SLXA in my 01 Civic EX, now I get P0740/P1773/P1776 codes & the car is in LIMP MODE.
I only get 1st/2nd gears back when I cancel codes w/$20 scan tool connected while driving.
Would an ECU swap be my resolve or can original ECU be coded to accept SLXA?
I only get 1st/2nd gears back when I cancel codes w/$20 scan tool connected while driving.
Would an ECU swap be my resolve or can original ECU be coded to accept SLXA?
07-10-2023
#12
Re: SLXA swap information
I swapped out a bummed BMXA for a SLXA in my 01 Civic EX, now I get P0740/P1773/P1776 codes & the car is in LIMP MODE.
I only get 1st/2nd gears back when I cancel codes w/$20 scan tool connected while driving.
Would an ECU swap be my resolve or can original ECU be coded to accept SLXA?
I only get 1st/2nd gears back when I cancel codes w/$20 scan tool connected while driving.
Would an ECU swap be my resolve or can original ECU be coded to accept SLXA?
The clutch pressure control solenoid is the dual solenoid on the front of the transmission. First, double check that it's connected properly. Unplug both plugs, look inside them for corrosion or other damage, and reconnect them carefully. Make sure both plugs click and make sure the brown plug goes to the brown solenoid and the black plug goes to the black solenoid because it is possible to mix them up.
If that doesn't work, try swapping that solenoid with the one from the old transmission. It's only held on by 6 bolts and is easily replaceable with the transmission in the car.
Last edited by D17VTECPOWER; 07-10-2023 at 05:40 PM.
07-10-2023
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The P0740 is expected with the JDM trans and won't cause limp mode or any other problems, but I don't think the P1773 or P1776 codes have anything with the transmission being JDM. From what I can tell, those are clutch pressure control solenoid circuit codes although there isn't much info on those codes.
The clutch pressure control solenoid is the dual solenoid on the front of the transmission. First, double check that it's connected properly. Unplug both plugs, look inside them for corrosion or other damage, and reconnect them carefully. Make sure both plugs click and make sure the brown plug goes to the brown solenoid and the black plug goes to the black solenoid because it is possible to mix them up.
If that doesn't work, try swapping that solenoid with the one from the old transmission. It's only held on by 6 bolts and is easily replaceable with the transmission in the car.
The clutch pressure control solenoid is the dual solenoid on the front of the transmission. First, double check that it's connected properly. Unplug both plugs, look inside them for corrosion or other damage, and reconnect them carefully. Make sure both plugs click and make sure the brown plug goes to the brown solenoid and the black plug goes to the black solenoid because it is possible to mix them up.
If that doesn't work, try swapping that solenoid with the one from the old transmission. It's only held on by 6 bolts and is easily replaceable with the transmission in the car.
I will swap out dud battery & see if maybe bad voltage to TCM/ECU but new solenoids were placed when swap was done.
07-10-2023
#14
Re: SLXA swap information
I borrowed a better scantool (Autel MX8o8s), ran diag & active tests on solenoids...heard them click on/off & scanner says all good... discovered dying battery.
I will swap out dud battery & see if maybe bad voltage to TCM/ECU but new solenoids were placed when swap was done.
I will swap out dud battery & see if maybe bad voltage to TCM/ECU but new solenoids were placed when swap was done.
When you say you installed new solenoids when you did the swap, do you mean you replaced the solenoids as an attempt to solve the problem or you replaced the solenoids preventatively? And which solenoids did you replace them with? Can't assume a part works just because it's new, especially with aftermarket stuff.
Why was the transmission replaced in the first place? Was it replaced because of similar codes and shifting problems?
Low voltage can definitely cause these types of problems, so hopefully the new battery solves the problems. Keep us posted!
07-12-2023
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I changed the 3 solenoids preventively; dual shift on the front, auto shift just above the trans pan drain, trans control unit on the top.
I refilled and checked the transmission fluid level, making sure not to overfill.
Original transmission was replaced because all forward gears appeared to be lost and reverse was slowly fading.
Currently, without the attached scan tool, I have difficulty at take offs (lower gear) but fine once i get up to 30/40 mph.
I refilled and checked the transmission fluid level, making sure not to overfill.
Original transmission was replaced because all forward gears appeared to be lost and reverse was slowly fading.
Currently, without the attached scan tool, I have difficulty at take offs (lower gear) but fine once i get up to 30/40 mph.
07-12-2023
#16
Re: SLXA swap information
I changed the 3 solenoids preventively; dual shift on the front, auto shift just above the trans pan drain, trans control unit on the top.
I refilled and checked the transmission fluid level, making sure not to overfill.
Original transmission was replaced because all forward gears appeared to be lost and reverse was slowly fading.
Currently, without the attached scan tool, I have difficulty at take offs (lower gear) but fine once i get up to 30/40 mph.
I refilled and checked the transmission fluid level, making sure not to overfill.
Original transmission was replaced because all forward gears appeared to be lost and reverse was slowly fading.
Currently, without the attached scan tool, I have difficulty at take offs (lower gear) but fine once i get up to 30/40 mph.
The solenoid on top of the transmission under the thermostat housing controls the torque converter lockup clutch, the dual solenoids on the front with the black and brown plugs control the line pressure, and the dual solenoids on the passenger side of the trans are the shift solenoids.
From your description of poor acceleration until you reach 30-40 MPH, it sounds like it's in limp mode and stuck in 4th gear, which is the gear these default to when a problem is detected and/or electronic control is lost.
If you manually downshift to 2nd gear when driving at low speeds or before taking off from a stop and shift it into drive once you are up to speed until the problem is fixed, the car will accelerate way better and put much less stress on the transmission and torque converter. Just be aware that this might set false codes with the JDM transmission. Taking off in 4th gear is the automatic equivalent of starting a manual car in 5th gear by slipping the clutch until you are up to speed and will quickly overheat the transmission and torque converter from the extreme slipping.
07-13-2023
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Aw man😳
ok I will reinstall the oems and see if things improve. That sux knowing “a good intent” has paved my hell road ride…
will make the swaps & let ya know what’s what
ok I will reinstall the oems and see if things improve. That sux knowing “a good intent” has paved my hell road ride…
will make the swaps & let ya know what’s what
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D17VTECPOWER (07-13-2023)
07-21-2023
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so not the solenoids & not the ECM (not directly) ...bad battery.
replaced battery & all is honkey dory...
no more CEL/codes, no more flashing gear indicator.
now i kinda wish it WAS one of the solenoids.
anyway thanks for the assist.
replaced battery & all is honkey dory...
no more CEL/codes, no more flashing gear indicator.
now i kinda wish it WAS one of the solenoids.
anyway thanks for the assist.
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D17VTECPOWER (07-22-2023)
09-14-2023
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I have an 01 civic ex and just got a slxa transmission for it without realizing there was the issue with the us ecu I’m curious if you think I should go on with the swap, I bought the car as a daily for $500 because it has a bad transmission, car has 240k on it and I’m worried that with the shorter gear ratios and I drive 60 miles on the highway daily if you think that’ll cause excessive wear to the engine as well.
Last edited by Claydylan44; 09-14-2023 at 01:32 PM.
09-14-2023
#20
Re: SLXA swap information
I have an 01 civic ex and just got a slxa transmission for it without realizing there was the issue with the us ecu I’m curious if you think I should go on with the swap, I bought the car as a daily for $500 because it has a bad transmission, car has 240k on it and I’m worried that with the shorter gear ratios and I drive 60 miles on the highway daily if you think that’ll cause excessive wear to the engine as well.
The engine wear is a non issue. It's not geared that short, 70 MPH in 4th gear is only around 3000 RPM, which is less than the EX 5 speed. I didn't like the higher cruising RPM at first, but once I got used to it, I ended up preferring it because I live in a hilly area and it climbed better with the shorter gearing and didn't have to downshift on every hill. I didn't lose any gas mileage either, presumably because it climbed easier. For a 4 speed, the JDM SLXA's gear ratios were great for the D17A2 IMO and that transmission served me well until I swapped it for a 5 speed manual, which I like better all the way around.
Hope this helps!
09-14-2023
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I would, there shouldn't be any serious issues using the US ECU. The only real issue I'm aware of is the P0741 engine light code since the US ECU won't understand the shorter gearing,
The engine wear is a non issue. It's not geared that short, 70 MPH in 4th gear is only around 3000 RPM, which is less than the EX 5 speed. I didn't like the higher cruising RPM at first, but once I got used to it, I ended up preferring it because I live in a hilly area and it climbed better with the shorter gearing and didn't have to downshift on every hill. I didn't lose any gas mileage either, presumably because it climbed easier. For a 4 speed, the JDM SLXA's gear ratios were great for the D17A2 IMO and that transmission served me well until I swapped it for a 5 speed manual, which I like better all the way around.
Hope this helps!
The engine wear is a non issue. It's not geared that short, 70 MPH in 4th gear is only around 3000 RPM, which is less than the EX 5 speed. I didn't like the higher cruising RPM at first, but once I got used to it, I ended up preferring it because I live in a hilly area and it climbed better with the shorter gearing and didn't have to downshift on every hill. I didn't lose any gas mileage either, presumably because it climbed easier. For a 4 speed, the JDM SLXA's gear ratios were great for the D17A2 IMO and that transmission served me well until I swapped it for a 5 speed manual, which I like better all the way around.
Hope this helps!
09-14-2023
#22
Re: SLXA swap information
Thank you for the quick reply! I was thinking about returning the transmission but now I’m thinking of doing the swap. I do also live in a pretty hilly area being in western WA. Would getting a jdm pcm fix the engine light? The place I bought it from is saying they’ll give me one for free but it’s also a bit of a drive out there. I just want to make sure it’s worth it to mob back out there. Also was wondering what modifications do you think I should do for this car to be more fuel efficient without going too crazy into it so I don’t have to buy a daily for my daily 😂
Keep in mind that both the VTEC and non VTEC 5 speeds have significantly shorter 5th gears than the US auto's 4th gear and it's generally accepted that the manuals get significantly better fuel efficiency under all driving conditions including cruising on the highway despite running at a noticeably higher RPM, so it's not as simple as it may seem.
If your goal is fuel efficiency, the single best mechanical mod you can do IMO is a 5 speed swap. I used to get around 35 MPG at best with either the US or JDM auto, but with the 5 speed swap, I get 40-42+ MPG without even trying and have gotten as good as 47-49 MPG when I put effort into driving efficiently. The VTEC engine with the taller geared non VTEC DX/LX/VP 5 speed trans seems to be a very fuel efficient combination.
Other than that, there's not much else you can easily do mechanically for huge improvements, most of your improvements will be from driver mods. Taking off the power steering pump belt or converting to EPS, weight reduction, aero mods, lighter wheels, and lower rolling resistance tires will certainly help while still possibly being practical for a daily, but don't expect anything huge unless you do something extreme. I have found that Ecomodder is a great resource if you want to learn more about improving fuel efficiency
09-14-2023
#23
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My experience has been that the stock gearing on the US auto was chosen for better results in the unrealistic EPA test cycle, not real world efficiency. It was fine for cruising at steady highway speeds with no hills, but it was frequently having to unlock the torque converter and/or downshift for hills, which isn't great since nothing here in TN is flat for very long.
Keep in mind that both the VTEC and non VTEC 5 speeds have significantly shorter 5th gears than the US auto's 4th gear and it's generally accepted that the manuals get significantly better fuel efficiency under all driving conditions including cruising on the highway despite running at a noticeably higher RPM, so it's not as simple as it may seem.
If your goal is fuel efficiency, the single best mechanical mod you can do IMO is a 5 speed swap. I used to get around 35 MPG at best with either the US or JDM auto, but with the 5 speed swap, I get 40-42+ MPG without even trying and have gotten as good as 47-49 MPG when I put effort into driving efficiently. The VTEC engine with the taller geared non VTEC DX/LX/VP 5 speed trans seems to be a very fuel efficient combination.
Other than that, there's not much else you can easily do mechanically for huge improvements, most of your improvements will be from driver mods. Taking off the power steering pump belt or converting to EPS, weight reduction, aero mods, lighter wheels, and lower rolling resistance tires will certainly help while still possibly being practical for a daily, but don't expect anything huge unless you do something extreme. I have found that Ecomodder is a great resource if you want to learn more about improving fuel efficiency
Keep in mind that both the VTEC and non VTEC 5 speeds have significantly shorter 5th gears than the US auto's 4th gear and it's generally accepted that the manuals get significantly better fuel efficiency under all driving conditions including cruising on the highway despite running at a noticeably higher RPM, so it's not as simple as it may seem.
If your goal is fuel efficiency, the single best mechanical mod you can do IMO is a 5 speed swap. I used to get around 35 MPG at best with either the US or JDM auto, but with the 5 speed swap, I get 40-42+ MPG without even trying and have gotten as good as 47-49 MPG when I put effort into driving efficiently. The VTEC engine with the taller geared non VTEC DX/LX/VP 5 speed trans seems to be a very fuel efficient combination.
Other than that, there's not much else you can easily do mechanically for huge improvements, most of your improvements will be from driver mods. Taking off the power steering pump belt or converting to EPS, weight reduction, aero mods, lighter wheels, and lower rolling resistance tires will certainly help while still possibly being practical for a daily, but don't expect anything huge unless you do something extreme. I have found that Ecomodder is a great resource if you want to learn more about improving fuel efficiency
09-14-2023
#24
Re: SLXA swap information
Awesome I appreciate all the info! So the place that I bought the auto slxa won’t return it so I’ll stick to that for now. I plan on keeping the car for awhile ( already bought new control arms, ball joints, subframe bushings, motor mounts, shocks, wheel bearings, and axles) so maybe the 5 speed will be in the future. I just want there to be no engine light i know it’s not a big deal, it’ll just bother me. I have a bluepoint obd2 reader, can I just delete the code with that? I’ve not used it too much so not sure if I can permanently remove codes. Would the jdm pcm solve that issue or would I need the jdm ecu aswell.
A JDM ECU will solve the P0741 code since it's programmed for the SLXA's gear ratios and I have used one from a Honda Stream for years, but the problems are too numerous for me to recommend it to anyone else. It will only work with the VTEC engine, the fuel pump relay uses a different pin so the ECU connector has to be repinned, the D3 mode is lost if not rewired, I had a flashing key light constantly because my Stream ECU had no immobilizer and I read that the immobilizer equipped JDM ECUs can't be programmed by US dealers although I haven't verified that, the o2 sensor wiring may or may not be the same depending on the year and which ECU you get, I don't think it supports the US OBD standard for emissions testing, etc. It can be done, but it's really not worth it.
I made a thread years ago documenting my experiences with using the JDM ECU and how I got around the issues as I found solutions. Unfortunately, a moderator deleted that thread, which is a shame because I put so much time and effort into figuring out the pinouts and wiring for myself since finding wiring diagrams for odd JDM cars is basically impossible in America and that information is now lost forever because I don't remember the pinouts, wire colors, etc.
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09-14-2023
#25
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I don't know of a permanent solution to the engine light. I have read that people have kept the light off for long enough to get the readiness monitors to set so it will pass inspection just by resetting the codes and driving for a few days at lower speeds (somewhere under 40-45 MPH if I remember correctly), but clearly that's not a permanent solution.
A JDM ECU will solve the P0741 code since it's programmed for the SLXA's gear ratios and I have used one from a Honda Stream for years, but the problems are too numerous for me to recommend it to anyone else. It will only work with the VTEC engine, the fuel pump relay uses a different pin so the ECU connector has to be repinned, the D3 mode is lost if not rewired, I had a flashing key light constantly because my Stream ECU had no immobilizer and I read that the immobilizer equipped JDM ECUs can't be programmed by US dealers although I haven't verified that, the o2 sensor wiring may or may not be the same depending on the year and which ECU you get, I don't think it supports the US OBD standard for emissions testing, etc. It can be done, but it's really not worth it.
I made a thread years ago documenting my experiences with using the JDM ECU and how I got around the issues as I found solutions. Unfortunately, a moderator deleted that thread, which is a shame because I put so much time and effort into figuring out the pinouts and wiring for myself since finding wiring diagrams for odd JDM cars is basically impossible in America and that information is now lost forever because I don't remember the pinouts, wire colors, etc.
A JDM ECU will solve the P0741 code since it's programmed for the SLXA's gear ratios and I have used one from a Honda Stream for years, but the problems are too numerous for me to recommend it to anyone else. It will only work with the VTEC engine, the fuel pump relay uses a different pin so the ECU connector has to be repinned, the D3 mode is lost if not rewired, I had a flashing key light constantly because my Stream ECU had no immobilizer and I read that the immobilizer equipped JDM ECUs can't be programmed by US dealers although I haven't verified that, the o2 sensor wiring may or may not be the same depending on the year and which ECU you get, I don't think it supports the US OBD standard for emissions testing, etc. It can be done, but it's really not worth it.
I made a thread years ago documenting my experiences with using the JDM ECU and how I got around the issues as I found solutions. Unfortunately, a moderator deleted that thread, which is a shame because I put so much time and effort into figuring out the pinouts and wiring for myself since finding wiring diagrams for odd JDM cars is basically impossible in America and that information is now lost forever because I don't remember the pinouts, wire colors, etc.
I’ve read in a few other places that using the BMXA range position sensor might solve that issue so I might give that a try.
luckily I do not have to deal with emissions testing here so it’s not really a worry on that part I just know with my 2012 wrx a CEL gets rid of cruise control and traction control and I don’t want to deal with that on this. Plus just having a clean dash would be nice for once 😂
09-14-2023
#26
Re: SLXA swap information
Im sorry about the thread going missing :/ I’m really thankful for all the information you have given me and I appreciate the time you’ve spent replying
I’ve read in a few other places that using the BMXA range position sensor might solve that issue so I might give that a try.
luckily I do not have to deal with emissions testing here so it’s not really a worry on that part I just know with my 2012 wrx a CEL gets rid of cruise control and traction control and I don’t want to deal with that on this. Plus just having a clean dash would be nice for once 😂
I’ve read in a few other places that using the BMXA range position sensor might solve that issue so I might give that a try.
luckily I do not have to deal with emissions testing here so it’s not really a worry on that part I just know with my 2012 wrx a CEL gets rid of cruise control and traction control and I don’t want to deal with that on this. Plus just having a clean dash would be nice for once 😂
The P0741 code has nothing to do with the range sensor anyways. What sets that code is the ECU doesn't understand why the RPM is somewhat higher than it expects on the highway and it clearly has no way to know that the transmission was replaced, so it just assumes that the RPM is high because the torque converter isn't locking up. If there was a way to program it to accept the JDM gear ratios, that would solve the problem. Unfortunately, the 7th gen ECUs aren't programmable, so there is no real solution other than replacing it with a JDM ECU and all the problems that come with that.
I have wondered if an ECU from a JDM Civic with 4 speed auto would work better than one from a Stream, but since most of the JDM 7th gen Civics came with the D15B and many of them a CVT, the only JDM D17A ECUs I was able to find were from the Stream (code PSA) and the Edix (code RJH), neither of which is very compatible with the Civic without lots of workarounds.
10-31-2023
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The BMXA range sensor won't work on an SLXA because the SLXA doesn't have a physical D3 position, so the positions are spaced further apart and won't line up with anything in the BMXA range sensor just like how the shifter won't line up.
The P0741 code has nothing to do with the range sensor anyways. What sets that code is the ECU doesn't understand why the RPM is somewhat higher than it expects on the highway and it clearly has no way to know that the transmission was replaced, so it just assumes that the RPM is high because the torque converter isn't locking up. If there was a way to program it to accept the JDM gear ratios, that would solve the problem. Unfortunately, the 7th gen ECUs aren't programmable, so there is no real solution other than replacing it with a JDM ECU and all the problems that come with that.
I have wondered if an ECU from a JDM Civic with 4 speed auto would work better than one from a Stream, but since most of the JDM 7th gen Civics came with the D15B and many of them a CVT, the only JDM D17A ECUs I was able to find were from the Stream (code PSA) and the Edix (code RJH), neither of which is very compatible with the Civic without lots of workarounds.
The P0741 code has nothing to do with the range sensor anyways. What sets that code is the ECU doesn't understand why the RPM is somewhat higher than it expects on the highway and it clearly has no way to know that the transmission was replaced, so it just assumes that the RPM is high because the torque converter isn't locking up. If there was a way to program it to accept the JDM gear ratios, that would solve the problem. Unfortunately, the 7th gen ECUs aren't programmable, so there is no real solution other than replacing it with a JDM ECU and all the problems that come with that.
I have wondered if an ECU from a JDM Civic with 4 speed auto would work better than one from a Stream, but since most of the JDM 7th gen Civics came with the D15B and many of them a CVT, the only JDM D17A ECUs I was able to find were from the Stream (code PSA) and the Edix (code RJH), neither of which is very compatible with the Civic without lots of workarounds.
10-31-2023
#28
Re: SLXA swap information
Here's a video of someone tearing down one of these transmissions so you can see where the filter is and how to get to it. The procedure is exactly the same for the BMXA and SLXA regardless of whether its USDM or JDM.
10-31-2023
#29
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These transmissions don't have a pan unfortunately, you have to split the case to get to the filter. If that's not something you are comfortable doing, you might want to see if you can find a local transmission shop to replace the filter before installing it because the filter clogging and killing the transmission is a common failure on these. At some point mid generation, I believe around 03 or 04, Honda realized this and started using improved larger filters, which seems to have helped the longevity of these transmissions judging by the lower failure rate of the later ones compared to the earlier ones.
Here's a video of someone tearing down one of these transmissions so you can see where the filter is and how to get to it. The procedure is exactly the same for the BMXA and SLXA regardless of whether its USDM or JDM. https://www.youtube.com/watch?v=1nKBEGUOu3M
Here's a video of someone tearing down one of these transmissions so you can see where the filter is and how to get to it. The procedure is exactly the same for the BMXA and SLXA regardless of whether its USDM or JDM. https://www.youtube.com/watch?v=1nKBEGUOu3M
Anyway, I have also heard that the later 7th gen transmissions were sort of ironed out but still could fail. I found an 05 BMXA transmission on eBay from a salvage yard with around 130k miles for about 900 bucks. The cheapest I've found a shop that could R&R a transmission is 740, assuming they do it correctly and use Honda fluid. Do you think that would be a better alternative to ordering the low mile JDM SLXA transmission that was, i assume, built with the smaller filter, and having to possibly pay extra for having the bigger filter put in? By no means can I pay for a full rebuild, and I'm not sure if I would be able to afford a partial rebuild with having a filter swap. My car completely stopped going into gear today as opposed to going into gear for about 30 seconds and then giving out, so I'm assuming just having the filter swapped out would only be a band-aid fix. I guess I just didn't want to believe my transmission needed to be rebuilt. 😂
10-31-2023
#30
Re: SLXA swap information
I see, thanks for the quick reply. Since my car broke down last month almost to the day, i've been researching this issue since every transmission shop I had talked to was saying basically the same thing that the internal filter had failed. I apologize for the first question I now see it was a stupid question to ask especially since I have been looking at several different transmissions for this generation and I can clearly see there's no pan. You can probably tell I don't know a whole lot when it comes to working on cars lol. Would like to though.
Anyway, I have also heard that the later 7th gen transmissions were sort of ironed out but still could fail. I found an 05 BMXA transmission on eBay from a salvage yard with around 130k miles for about 900 bucks. The cheapest I've found a shop that could R&R a transmission is 740, assuming they do it correctly and use Honda fluid. Do you think that would be a better alternative to ordering the low mile JDM SLXA transmission that was, i assume, built with the smaller filter, and having to possibly pay extra for having the bigger filter put in? By no means can I pay for a full rebuild, and I'm not sure if I would be able to afford a partial rebuild with having a filter swap. My car completely stopped going into gear today as opposed to going into gear for about 30 seconds and then giving out, so I'm assuming just having the filter swapped out would only be a band-aid fix. I guess I just didn't want to believe my transmission needed to be rebuilt. 😂
Anyway, I have also heard that the later 7th gen transmissions were sort of ironed out but still could fail. I found an 05 BMXA transmission on eBay from a salvage yard with around 130k miles for about 900 bucks. The cheapest I've found a shop that could R&R a transmission is 740, assuming they do it correctly and use Honda fluid. Do you think that would be a better alternative to ordering the low mile JDM SLXA transmission that was, i assume, built with the smaller filter, and having to possibly pay extra for having the bigger filter put in? By no means can I pay for a full rebuild, and I'm not sure if I would be able to afford a partial rebuild with having a filter swap. My car completely stopped going into gear today as opposed to going into gear for about 30 seconds and then giving out, so I'm assuming just having the filter swapped out would only be a band-aid fix. I guess I just didn't want to believe my transmission needed to be rebuilt. 😂
Just don't be mislead by low mileage. First of all, there is no good way to verify that the advertised mileage on some eBay listing is actually correct. That would be a very easy thing to lie about. And even if it does truly have only 130K miles, if those were hard city miles sitting in stop and go traffic, there could easily be more wear on that transmission than one with several times that mileage that spent most of its life cruising down the highway in 4th gear, but verifying either would be hard enough in person let alone through an eBay listing. With transmissions, maintenance history and total shifts are what counts, not really mileage. I would think a lot of city miles would generally be a safe bet with anything from Japan since so much of the country is so crowded, but again, no way to actually verify.
As for whether the JDM transmissions have the large or small filter or whether it depends on the year, I'm not sure. Mine had the small filter, but since JDM stuff doesn't have a VIN tag, I have no way to know what year it was made. You might be able to see the filter with a borescope through either the dipstick hole or the drain hole, but I can't say for sure since I never tried that. Either way, with these transmissions being 18-23 years old and known for clogging filters well over a decade ago, I'd still suggest changing the filter before installation if possible.
Last edited by D17VTECPOWER; 10-31-2023 at 09:14 PM.
