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Mechanical Problems/Vehicle Issues and Fix-it ForumIf you've got a problem you just can't figure out, a noise you can't diagnose, or a Check Engine Light that won't go away, ask about it here!
OK I'm frustrated. Did an engine & tranny swap replaced original 1.7L vtec engine, and tranny, used same year and style 2002 civic ex nothing fancy just wanted lower miles. Lets shorten the story- took 4 hours to remove and next day about same time to set the replacement into the civic 🤜🤛 hooked up wires hoses sensors filled fluids connected battery said a prayer🙏 🤞turned the key and👏🤝💪 beautiful hum smooth idle!! perfect!! We left this baby to run about 15 got in to drive it out of garage😱😟 only will go in reverse??😒 we can't even feel the shifting of gears when going through park neutral drive and lower gears. No engine light on dash all connections look good🙇😩 OK well the original tranny worked great so the decision was made to place original (2year old)tranny back in. Few more hours of work on day 3.. Again, made sure all connections secure in the correct positions wires were secure nothing loose frayed touching etc. Battery was hooked back up and again😬🙏🤞started her up!! Again we had a smooth start and nice hum. After a minute or two we got a code and hopes were dashed. Decided up shift through gears anyway and we can hear engagement this time that was a relief. Before running diagnostic of the check engine light we attempted to drive out the back out of the garage was smooth. We shifted into drive it sounded great then have her gas, this showed first issue the car was not going into first nor second automatically we are having to manually shift into gear then will engage into higher gear on its own?? I drive into garage again to scan the car The code is p1773 which turns out to not be a mechanical issue but an issue with the shift solenoid particularity valve B. The ground is secure and the wires are correctly placed into valves and PCM. We've tested the solenoid and the clicking is there the valves move and now I'm lost. I took the civic to one of those transmission franchises, explained in detail even have them code after 5 days of no word I went in and was told my PCM needs replacement because my speed sensor is switching off and on when it should have been in off position only! Now I'm more confused? Why am I not getting a code for my speed sensor they had no answer and told me it would cost a grand to get done. I can always find the identical computer have the immobilizer done and installed alot cheaper, but I feel in my gut this is not going to fix the issue of the computer and solenoid communicating with automatic transmission! Does anyone have any other helpful possibilities!
that was actually my first concern, no I checked all solenoids they are matched and fully wired in, I've tested the clutch and shift solenoids are clicking with test. I was told by one shop there may be a fray or bunch or minor twist somewhere in a wire when they did more thorough diagnostic. He's retired so it's alot of work physically so I did the checking of the wires under his eye & all good, well I manually drove the civic to a big transmission franchise. I explained the issue and after 2 days and a weekend they stated my PCM is done for!! their reason was when they tested the computer the connection for civics speed sensor was reading off/on off/on and it should have stayed in the off position!? I now the speed sensor tells the solenoids to get busy doing your job of shifting but my concern is if my computer is done would it even give a reading to start with? And if it still will give a diagnostic reading would it not give me a code that my speed sensor is not working since that is the only one that I was told is not working correctly on the computer? Let me add that the speed sensor was checked and is working! Also there's not one other issue! the engine is smooth quiet and strong.. I'm considering a3rd opinion but would like some fellow civic owner feedback on if this may have ever happened or has any ideas to try?
If you think a good mechanic is expensive, try hiring a bad one
Joined: Dec 2011
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From: Midwest. Aiming about mid-chest
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Re: 2002 civic engine swap no AT shift p1773
speed sensor was reading off/on off/on
That's how a square wave works. You have a service manual and volt-ohm meter?
a big transmission franchise.
Why are they messing with a speed sensor when the code is for a CPC solenoid?
That's the last place you want to go. Get your car away from them.
P1773 is defined as an electrical problem with Clutch Pressure Control solenoid B circuit, , it cannot be caused by a mechanical problem in the transmission.
So your possible causes will be the solenoid itself, wiring issues, or PCM. (Rule of thumb: it's never the pcm)
A big problem in trying to diagnose trans solenoid issues such as this is choosing the wrong solenoid when testing. There are several with somewhat similar names. I always check wiring diagrams and component locations and verify wire colors match what I think I'm supposed to be checking.
CPC B is the upper of the pair.
Wire colors brn/wht and blk/red
That's how a square wave works. You have a service manual and volt-ohm meter?
Why are they messing with a speed sensor when the code is for a CPC solenoid?
I do not know I asked if they tested the worrying and they stated it looked good so they decided to test the diagnostic from start up. I just thanked them and left when more confused because
1 I always disconnect battery before any work, ALWAYS!
2 I would have thought a bad computer wouldn't even be reading this p1773 code at all
3 the computer is not making any sort of tick when reading the sensors (I may be wrong on that but was told the PCM will make a tick sound if stuck reading any code)
4 I was told numerous times over the years that someone is more likely to hit the lottery than need to replace a PCM.
That's the last place you want to go. Get your car away from them.
I did take it, paid 95 bucks and ended up more confused
P1773 is defined as an electrical problem with Clutch Pressure Control solenoid B circuit, , it cannot be caused by a mechanical problem in the transmission.
So your possible causes will be the solenoid itself, wiring issues, or PCM. (Rule of thumb: it's never the pcm)
A big problem in trying to diagnose trans solenoid issues such as this is choosing the wrong solenoid when testing. There are several with somewhat similar names. I always check wiring diagrams and component locations and verify wire colors match what I think I'm supposed to be checking.
CPC B is the upper of the pair.
Wire colors brn/wht and blk/red
Solenoid resistance spec 3-10 ohms
I haven't checked the ohms but I will do that my question is if the any reading is higher or lower how is that then repaired? I do know the wires are matched, the plugs are correct and the valves move in and out. Also should I test the PCM? And do they have to match up with each sensor's ohm reading number? This is a pain in the *** but this 02 is my baby my dream car and I've been keeping her young and vibrant in not giving up!! Thanks you both for all the help, I also forgot to ask, is it possible that maybe the software needs to be reset in the PCM?
If you think a good mechanic is expensive, try hiring a bad one
Joined: Dec 2011
Posts: 32,017
Likes: 256
From: Midwest. Aiming about mid-chest
Rep Power: 518
Re: 2002 civic engine swap no AT shift p1773
Originally Posted by Pzern
2 I would have thought a bad computer wouldn't even be reading this p1773 code at all
Not necessarily.
3 the computer is not making any sort of tick when reading the sensors (I may be wrong on that but was told the PCM will make a tick sound if stuck reading any code)
Incorrect. It better be completely silent.
4 I was told numerous times over the years that someone is more likely to hit the lottery than need to replace a PCM.
This is usually true. Usually.
Hondas PCMs are pretty robust, but not bulletproof.
I haven't checked the ohms but I will do that my question is if the any reading is higher or lower how is that then repaired?
Depends on what is wrong.
Also should I test the PCM?
Gonna be kinda tough if you don't know what you are doing, don't know how the pcm controls that CPC solenoid, don't know what the PCM has to see wrong in order to judge a failure, don't have a scanner that can display that live trans data, etc. IOW not always, it's usually judged by process of elimination.
I think you better get yourself a service manual so you can follow hondas diag trouble tree.
I also forgot to ask, is it possible that maybe the software needs to be reset in the PCM?
You can't touch software.
You DO need to erase the code and see if it returns (now, and again after every repair attempt), that's gonna be the only way you know if the PCM is finally happy with what it sees.
You have a code reader?
If you still have the other transmission you could take the solenoid set off of it and plug it into your cars harness, erase the codes and see if the same code still resets.
