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I've got an 02 Civic EX that I recently was given by a neighbor. I've been trying desperately to get it to start. The following is a list of things that have been checked and or replaced.
Things to note:
1. I hear no audible sound coming from the fuel pump when the ignition is turned. I replaced the fuel pump. no fix.
2. I tested both the wire side and the female side of the PGMFI 1 and 2 relays in the glove box. both have good current.
3. I have tried starting it with starting fluid, it starts and runs for a second and then dies. That's what makes me think it's fuel starvation
4. The immobilized key lights up and then goes off as usual, only flashes green when the ignition is turned off and the key is taken out. For about 2 seconds that is.
5. Fresh fuel was put in the tank, along with a bottle of HEET.
6. Battery is new....
I'm getting kind out of hope here. What else could be causing the fuel pump not to prime?
Any help would be greatly appreciated
Fuel pump will only prime for a couple seconds after key on. Stock fuel pump is fairly quiet as well, are you just missing it? Unplug the fuel pump and see if there is voltage when key is turned on.
I can test that, but both the replacement and the OEM are SILENT.
Only noise I can hear sounds like the stereo or climate control. It's definitely coming from behind the dash. I even stuck my ear to the fuel filler neck with the cap off to see if I could hear a buzz
I'm starting to wonder if it's an immobilizer issue, but the green key light cuts on then off as it's supposed to do when the key is inserted. Then flashes about 5 times after i turn the ignition back off and take it out...is that normal?
I finally got a chance to get back to the Civic with the voltmeter. Upon testing the voltage at the ground lead on the fuel pump connector, I'm getting strange fluctuations of between .5 and 1.2. I've read this number isn't supposed be above .5 volts...
Upon testing the positive side of the connector, I'm getting somewhere in the neighborhood of 8v.
Does any of this make sense? I'm shooting from the hip here, I don't usually mess with electrical systems....I'm more a wrench guy.
bring a 12V battery and directly connect to the pump, it that works the wiring is not good.
Multimeters can test continuity
Pump works with battery.
Okay, so I went back to test the connector again, now I'm getting 12v on the hot side, but mysteriously getting flat readings on the ground side. Also not getting a continuity between pins 4 and 5 on the fuel pump harness.
I guess my next question is, do i start pulling up carpet and chasing wires or is there something else between the fuel pump and the relay that could be a problem?
Okay, so I went back to test the connector again, now I'm getting 12v on the hot side, but mysteriously getting flat readings on the ground side.
12V on hot side, good. Flat readings on ground side?? You mean 0V which is exactly what ground should have?
Originally Posted by MuddFlapps
Also not getting a continuity between pins 4 and 5 on the fuel pump harness.
Were you expecting to? There should not be continuity between 4 and 5 on the harness side. You should be able to measure battery voltage between the two (when the pump is turned on).
12V on hot side, good. Flat readings on ground side?? You mean 0V which is exactly what ground should have?
Were you expecting to? There should not be continuity between 4 and 5 on the harness side. You should be able to measure battery voltage between the two (when the pump is turned on).
Okay, I don't know how this all got so mangled. I think it had to do with a combination of me drinking and trying to post this from my phone.
Here is the official Honda factory service manual procedure that I followed to troubleshoot the PGM-FI system.
With the ignition switch ON:
The voltage between PGMFI relay 2 terminal 5 and the battery ground is ~12.4v
The voltage between PGMFI relay 2 terminal 1 and the battery ground is ~12.4v
With the ignition switch OFF:
There IS continuity between PGMFI Relay 2 terminal 5 and ECM Connector terminal E1
With the PGM-FI relay 2 reinstalled, and the ignition turned to ON:
**WHEN MEASURING VOLTAGE BETWEEN ECM CONNECTOR TERMINAL E1 AND BATTERY GROUND, VOLTAGE READS A STEADY 0.61v. NOT ~12.4v "BATTERY VOLTAGE"** (This is the first strange thing i've noticed so far). Now, at this point Honda says to replace the PGM-FI relay 2 if it isn't getting "battery voltage". Ive tested the relay with a drill battery and the voltmeter and everything SEEMS to be in order with it? Moving past that, on account of not knowing if this was normal or truly a bad relay; I moved to the next step "assuming" that was correct.
With PGM-FI relay 2 reinstalled, the ECM connector plugged back in, and the ignition On:
When measuring the voltage between ECM Connector terminal E1 and the battery ground within the first 2 seconds of turning the ignition on, there IS battery voltage.
Honda says if there IS battery voltageto either update the ECM or substitute it for a known good ecm at this point. I am off to check the voltage on the fuel pump connector between terminal 5 and the battery ground....
The voltage between PGMFI relay 2 terminal 5 and the battery ground is ~12.4v
The voltage between PGMFI relay 2 terminal 1 and the battery ground is ~12.4v
Both of these are good.
Originally Posted by MuddFlapps
With the ignition switch OFF:
There IS continuity between PGMFI Relay 2 terminal 5 and ECM Connector terminal E1
Typo? You should be checking continuity from relay terminal 3 to ECM terminal E1.
Originally Posted by MuddFlapps
With the PGM-FI relay 2 reinstalled, and the ignition turned to ON:
**WHEN MEASURING VOLTAGE BETWEEN ECM CONNECTOR TERMINAL E1 AND BATTERY GROUND, VOLTAGE READS A STEADY 0.61v. NOT ~12.4v "BATTERY VOLTAGE"** (This is the first strange thing i've noticed so far). Now, at this point Honda says to replace the PGM-FI relay 2 if it isn't getting "battery voltage". Ive tested the relay with a drill battery and the voltmeter and everything SEEMS to be in order with it? Moving past that, on account of not knowing if this was normal or truly a bad relay; I moved to the next step "assuming" that was correct.
Did you still have connector E disconnected when testing this? Service manual never instructs to plug it back in. If it were plugged in, it should read close to 0V. Without getting the expected result here, I would not continue any further into the troubleshooting until it can be explained why.
Typo? You should be checking continuity from relay terminal 3 to ECM terminal E1.
Did you still have connector E disconnected when testing this? Service manual never instructs to plug it back in. If it were plugged in, it should read close to 0V. Without getting the expected result here, I would not continue any further into the troubleshooting until it can be explained why.
Yes, that was a typo because of the fact that the connector is viewed from the wire side.
As for the other question, I've tested the voltage between ECM terminal E1 and the body ground with the connector DISCONNECTED and the ignition ON and get a voltage of 0.61v. With the connector PLUGGED IN in and the ignition ON I'm getting a reading of 0.07v.
We did skip a step. Check continuity between E1 and pin 3 at the relay connector. This should read very low ohms, less than 10. If this checks out, it points to a failed relay. I cannot remember what size this relay is but you could look for a known good one in the under-hood box to swap with. Would be a good test anyways.
I actually just picked up an 01 Honda civic with the exact same issue currently traced it down to the fuel pump. I took the fuel pressure line off the fuel rail and there is no flow when I try to start it. I’m going to test to make sure I’m getting power to it but after testing the fuses I’m thinking it’s the pump itself. When I spray starting fluid in the intake it starts right up then Bogs and dies down.
We did skip a step. Check continuity between E1 and pin 3 at the relay connector. This should read very low ohms, less than 10. If this checks out, it points to a failed relay. I cannot remember what size this relay is but you could look for a known good one in the under-hood box to swap with. Would be a good test anyways.
So, after going back and checking that last step, It looks like I've got perfect continuity, dips all the way down to 0. Tried looking under the hood for a comparable relay but it looks like all I've got it 4 terminal relays. Looks like I'm off to AutoZone to reduce my wealth by $27.99
So, went and got a replacement relay. No dice. Car still wont start.
The car cranks, sputters like its trying to start slightly but will only start for ~1.5 seconds then die. I dont know which direction to turn my attention towards.
the spark plugs are a little ugly. Any ideas?
If you're positive the fuel pump is not running, that is the place to start. From everything you said it should be a bad relay. With the new relay installed, are you still seeing 0V at pin E1 with key on?
Try removing the relay and jumping pins 1&2. That should turn on the fuel pump by bypassing everything going to the ECM.
If you're positive the fuel pump is not running, that is the place to start. From everything you said it should be a bad relay. With the new relay installed, are you still seeing 0V at pin E1 with key on?
Try removing the relay and jumping pins 1&2. That should turn on the fuel pump by bypassing everything going to the ECM.
OKAY, FINALLY!
After conecting the jumper wire, the fuel pump engaged and the car started!!!! Thanks for all the help so far, I owe you one. Now that we know where the problem is, what could be causing it? Is it the ECM? The relay has been replaced with a new one!
We know main relay 1 (the one right next to the jumper you added) is good, otherwise the car wouldn't have started. Either the main relay 2 (coil side) is missing power, missing ground, or the new relay is faulty. Power comes from main relay 1 so I'd like to think that's not the issue. Ground comes from the ECM pin E1. Here are three things to try:
-Install the new relay, unplug ECM connector E, ignition on. Measure voltage on pin E1 with respect to ground like you were doing previously. You should see battery voltage. You were getting 0V before which is why I suspected the relay.
-You could check the ground from the ECM as well. Remove main relay 2, make sure ECM connector E is plugged in, ignition on. Check continuity to ground in relay pin 3. If you have continuity, ECM should be good.
-Try removing main relay 1 (the one right next to the jumper you added), put the new relay in it's place. Does the car still start with your jumper installed? This would indicate the new relay is good.
We know main relay 1 (the one right next to the jumper you added) is good, otherwise the car wouldn't have started. Either the main relay 2 (coil side) is missing power, missing ground, or the new relay is faulty. Power comes from main relay 1 so I'd like to think that's not the issue. Ground comes from the ECM pin E1. Here are three things to try:
-Install the new relay, unplug ECM connector E, ignition on. Measure voltage on pin E1 with respect to ground like you were doing previously. You should see battery voltage. You were getting 0V before which is why I suspected the relay.
-You could check the ground from the ECM as well. Remove main relay 2, make sure ECM connector E is plugged in, ignition on. Check continuity to ground in relay pin 3. If you have continuity, ECM should be good.
-Try removing main relay 1 (the one right next to the jumper you added), put the new relay in it's place. Does the car still start with your jumper installed? This would indicate the new relay is good.
Looks like I'm getting 0.53v when measuring pin E1 and ground.
As for the ground on the ECM, definitely something up there. Terminal 3 is giving me readings as high as 2.23kΩ
After doing the relay switcharound the situation is the same. I tried with another relay under the hood.
Looks like I'm getting 0.53v when measuring pin E1 and ground.
I don't understand why this isn't reading battery voltage. It somewhat depends of the other two tests though.
Originally Posted by MuddFlapps
As for the ground on the ECM, definitely something up there. Terminal 3 is giving me readings as high as 2.23kΩ
I just realized, you will only have continuity to ground for the first few seconds after key on and then continuously while the engine is running.
Originally Posted by MuddFlapps
After doing the relay switcharound the situation is the same. I tried with another relay under the hood.
So, jumper installed in place of main relay 2. New relay from parts store in place of main relay 1? And it starts? The point of this test is to confirm the new relay works by putting in place of relay 1 because you know the car starts (with the jumper installed in place of relay 2). Shouldn't be using a relay from under-hood.
I just realized, you will only have continuity to ground for the first few seconds after key on and then continuously while the engine is running.
So, jumper installed in place of main relay 2. New relay from parts store in place of main relay 1? And it starts? The point of this test is to confirm the new relay works by putting in place of relay 1 because you know the car starts (with the jumper installed in place of relay 2). Shouldn't be using a relay from under-hood.
I can only swap a relay from under the hood, as relay 1 is a 4 terminal relay, and relay 2 is a 5 terminal relay. Therefore, I had to use one from under the the hood to replace it as relay 2 can't physically fit into relay 1's position. That being said, with BOTH relays substituted for different relays, nothing happens without the jumper wire.
I'm STILL getting no continuity at pin 3 on the relay terminal
Schematic shows they're both normally open, four pin relays. Relay 1 and 2 should both be identical. If you have an auto transmission, there will be at least one other relay in this same area. Are they getting mixed up?
This is getting to the point where I'm not sure how much more I can do without the car in front of me. Just so we're on the same page, here is the schematic I've been using.
-Relay 1 circled in red we assume is good. Why? When a jumper is in place of relay 2, the car starts. Relay 1 powers relay 2 coil, the ECM, and a bunch of sensors. You also measure battery voltage on relay 2 pin 4.
-What's circled in blue is assumed good as well. Why? When a jumper is in place of relay 2, the fuel pump runs and the car starts.
-The only things in question are:
Faulty relay 2
You replaced this but I hate to assume the new one is good. Not getting battery voltage on E1 with ignition on and relay 2 in place also indicates something is wrong here (or the wire to ECM).
The wire from relay 2 pin 3 to ECM pin E1
You previously checked continuity on this wire and measured 0 ohms. Could still be a spread/damaged terminal.
Faulty ECM
With E1 connected you're not getting continuity to ground for a few seconds immediately after the ignition is turned on. With connector E unplugged and ignition on, try jumping E1 to ground. Does relay 2 click and the fuel pump turn on?
Just to make sure there is no confusion, you keep saying relay pin 5 but the service manual shows 4. This picture is also the wire side of the connector (opposite side the relay plugs into). Are you checking the correct pins?
*Ignore the line going from pin 4 to ground. This was pulled from a troubleshooting step. Relay 1 is on the right in this picture.
I will say you seem very competent so far. It is a good change of pace from most others we see on the forum
Last edited by BrotatoChip; Mar 24, 2023 at 11:38 AM.
Reason: Accidently said relays were normally closed!
Schematic shows they're both normally open, four pin relays. Relay 1 and 2 should both be identical. If you have an auto transmission, there will be at least one other relay in this same area. Are they getting mixed up?
This is getting to the point where I'm not sure how much more I can do without the car in front of me. Just so we're on the same page, here is the schematic I've been using.
-Relay 1 circled in red we assume is good. Why? When a jumper is in place of relay 2, the car starts. Relay 1 powers relay 2 coil, the ECM, and a bunch of sensors. You also measure battery voltage on relay 2 pin 4.
-What's circled in blue is assumed good as well. Why? When a jumper is in place of relay 2, the fuel pump runs and the car starts.
-The only things in question are:
Faulty relay 2
You replaced this but I hate to assume the new one is good. Not getting battery voltage on E1 with ignition on and relay 2 in place also indicates something is wrong here (or the wire to ECM).
The wire from relay 2 pin 3 to ECM pin E1
You previously checked continuity on this wire and measured 0 ohms. Could still be a spread/damaged terminal.
Faulty ECM
With E1 connected you're not getting continuity to ground for a few seconds immediately after the ignition is turned on. With connector E unplugged and ignition on, try jumping E1 to ground. Does relay 2 click and the fuel pump turn on?
Just to make sure there is no confusion, you keep saying relay pin 5 but the service manual shows 4. This picture is also the wire side of the connector (opposite side the relay plugs into). Are you checking the correct pins?
*Ignore the line going from pin 4 to ground. This was pulled from a troubleshooting step. Relay 1 is on the right in this picture.
I will say you seem very competent so far. It is a good change of pace from most others we see on the forum
Thanks, I appreciate it. Electrical is not my strong suit, haha.
I tried jumping E1 to ground as you mentioned; nothing happening at the relay. I guess the last thing to do is chase down the wire from relay 2 pin 3 to ECM pin E1 and see if theres anything readily apparent that's wrong with it. I'll check to see if any of the terminals are splayed out. I guess its always possible I could have opened one up too much with the multimeter or something.
Also, the pgm-fi relay 2 terminal I've been referring to as "5" is labeled that way in my manual for some reason? I'm guessing it's because of the fact that relay 2 is a 5 terminal as opposed to relay 1 which is a 4 terminal....?
OKAY, so finally found out what the problem was. I took an ECM out of an 03 Civic EX at the junkyard, plugged it in to test if the fuel pump worked and it DID!. All I did was desolder the IC240 chip from the new ECU, and now I have a running Civic!
I'm guessing it's because of the fact that relay 2 is a 5 terminal as opposed to relay 1 which is a 4 terminal....?
