Hi All,

This is my first post. I have used the knowledge in this forum many times and appreciate all your help greatly!

The saga started about 5 months ago when the accord would not start, it would turnover but not start. The mail relay was only clicking once in key position II and the fuel pump would not prime for 2 sec as it should. I tested the main relay and it was good so I thought it was the fuel pump and replaced it. It ran great for about 2 months and then would failed to start again. Similarly it would turn over but would not send power to the fuel pump. I checked all fuses both under the hood as well as the driver kick panel. As I was testing I noticed that I if I jiggled the key I could get the main relay to click a second time and the fuel pump would prime and the car would start. Because of this I thought it was the ignition switch so I replaced it -- the car ran great for another couple months until recently.

A week ago, I try to start it the day after the first rain of the fall without any luck. It will turnover but the main relay only clicks once and the fuel pump will not prime. I tried jiggling the key without any luck. I checked every fuse again, all were good. I bought a new main relay, just to make sure, and it did not help. I cleaned all grounds I could find in the engine bay (although I am sure I missed some) and made sure I found and cleaned the main ECU ground. I also looked over the ECU circuit boards to make sure there was no visible issues with the solder points--all looked good and dry. The CEL was not turning off and there are no ECU codes when I jumped the blue connector under the glove box. Then today as I had the fuel pump unplugged I checked again if there were ECU codes and there were still none but after I pulled out the jump wire and turned the key to position II the main relay clicked twice paused and then again as it should with out the CEL light...I was shocked! I plugged the fuel pump back in and it worked, and the car started. Since then I have been testing it a bunch and sometimes on first key try after sitting a bit it will not prime the fuel pump but if I jiggle the key the relay clicks and the fuel pump primes.

I wonder if there is a humidity factor because the weather has been nice since the rain. It seems to be related to the jiggling of the key now but did not work the day after the rain.

Is there another component related to the key/ignition switch I should test? This is the part I have already replaced: http://thumbs3.ebaystatic.com/d/l225...jOZ3a53s-g.jpg

Could it be a bad ground or intermittent ECU issue?

What test do you recommend?

Thank you all for any help you can offer...I am so frustrated it is keeping me up at night!

 

Problem points toward an electrical problem in the ignition switch circuit. It could be a faulty switch (new), connector, or damaged wire.

You could bypass the ignition switch wiring w/ jumpers to see if problem can be isolated.

Is there any type of security interlock on this vehicle? If yes, this needs to be explored.

good luck

 

Thanks for your reply.

What process would you recommend to bypass the ignition switch w/ jumpers?

I am not sure what a security interlock is. How do I determine this?

One thing I forgot to mention is that within the last couple days the keyless entry will not lock the doors... it will arm the car and will unlock the doors if they are manually locked. The ongoing no start issue occurred prior to this (keyless entry not locking doors) issue.

Thanks again.

 

Remove steering wheel cover, disconnect electrical switch connector and jump appropriate wires (wiring diagram is necessary).

If you have a Honda keyless entry, you have a security system. There is a separate manual for this system which I don't have and the starter wiring diagram does not depict an interface w/ security system in the shop manual.

I had a 94 EX w/ factory keyless entry and it would set an alarm but I never saw any interaction w/ starting system, however there likely was a connection. I quit using when keyfob broke down from use.

Most security systems disable the fuel injection system (deny power to fuel pump) somehow.

good luck

 

Where is the best location to find correct year wire diagrams?

Not sure where to start with the diagnosis... Any detailed description would be much appreciated.

It seems to be that turning the key a couple times to position II or jiggling the key in position II starts the fuel pump prime and the car will start.

 

We just had another rain storm and the accord will not start -- so the rainy weather is a factor!

What is the best way to test the ignition switch components to rule out a failure?

Also, I tried testing the new fuel pump I installed by connecting power and ground from a standalone car jump-start battery just to see if it would run but it did not and I am not sure why? I thought if you connect power and ground the fuel pump motor should run...right? When I reconnected it to the car the pump ran fine, prior to the last rain.

Is there something connected to the fuel pump housing like the float gauge that could cause issues?

 

Pin 1 on the Main Fuel Relay (green/black wire) gets a ground signal from the PCM to send power to the fuel pump. You can backprobe that wire and use a volt meter to test continuity to ground when the car isn't starting. That wire is grounded at pin A16 on the OBD2 connector on your PCM to turn on the fuel pump.

May want to check that pin A16 on the PCM to see if it loose or there is corrosion. Or you can try to trace the board to from pin A16 to closely inspect the solder of the components. (Your problem sounds like an ECU issue to me, but you should test before replacing parts).

Not sure why you had a problem getting the fuel pump to run off the external battery. What wire colors were you powering/grounding and where were you doing this?

 

Hi PAhonda, I appreciate you post and sharing your knowledge!!!! It is very much appreciated!

I reviewed the wires on the Main Fuel Relay and it looks like Pin 1 is a white wire with green stripe. There is a green/black wire connected to Pin 8. What wire is the correct one I should backprobe?

Attached are 2 photos of my relay wires/pins:



During the backprobe test, what position should the key be in? I am new to using a volt meter but just got one for this task. So I am clear, I should set the meter to continuity and then put the red prob on the wire and the black one on a ground? How do I confirm if it tests good or bad?

Regarding the PCM - where is it located? Is it separate from the ECU? I found the ECU on the passenger floor.

Once I find the PCM what is the best way to identify pin A16?

When I tested the new fuel pump in the car, I disconnected the top wire harness that has 2 wires, one solid black and one black/yellow- I connected on alligator clip from the red power connector on the jumper battery to the terminal where the black/yellow wire was connected and another alligator clip from the black connector on the jumper battery to the the terminal where the solid black wire was connected.

Sorry for all the questions as I am new to electrical work...I appreciate your help more than I can explain in words

 

Pin 1 is the lower right wire on the second picture. The 96 accord doesn't have an ECU, it is the first year the Accord had a PCM (ECU and TCU combined in one unit).

For the backprobe test, the red meter lead will be connected to the grn/blk wire, black meter lead will be connected to a good ground (any bare metal bolt). You want to set the meter to resistance or continuity (open/closed) circuit. You want to test with the key turned to the start position.

 

Thanks for explaining, I will check the green/black wire and will report back. I was confused because there is an "8" by that wire on the relay.

To confirm, I should test in the "start" position with the car turning over? Should I also test it in key position II for the 2 second fuel prime?

So I guess what I thought was the ECU is the PCM! Thank you for clarifying.

How can I identify the pin A16? Is there a diagram available online for the PCM?