I found the blue two pin connectors on my car but there are TWO sets of them attached secured to a single blue holder . Which of these do you jumper to get the codes. I don't want to jumper the wrong one. Which color wires should I be looking for?

Problem I'm having is that car was running fine, starting fine. Parked it tried to start it up the next day and it will crank fine, but no sign of firing up.

130k miles.

 

Two wire, left plug iirc

 

Thanks Mad Mike

I used a paper clip but when I turned on the key to acc the CEL lamp stays on steady and does not blink.

Also without the jumper in when the key is turned to acc the cel lamp stays on constantly.

Any clues?

 

http://techauto.awardspace.com/ecu.html

 

Also noticed something else

The "drive" indicator will flash as well in the transmission selector indicator .

Would this also cause a no start?

 

Thanks for the amazing diagnostic checks link.

My CEL light is on solid when when jumpered and in acc position....

I wonder if the main relay directly powers the ECU?

 

If the D4/S light is flashing or on that is a code set by the TCU for the A/T. Any codes will blink from the respective light. It would not cause a no start issue, unless the TPS sensor was completely out of whack.

Jump the blue wire look for blinks/codes from the CEL/ABS/D4 lights and record.

Check the wiring to the ECU, there is a pin that corrodes and can cause issues. Make sure nothing is damaged in the wire harness.

Any recent work done? Check that part/area first.

 

I will report back with the blink codes from the transmission.

Like I said before the CEL light is on solid when turning the key to accessory position and when I attempted to jumper the service port. The transmission d4 indicator did flash (but I didn't realize that it too can report fault codes)

Really strange because the car was performing perfectly fine for the last couple of years until I shut it down the yesterday. I didn't notice any performance issues at all before this sudden no start situation. No wet weather recently....

Only work done recently was radiator early last year.


I did remember something minor at the time...Last year on occasion when cold the car would take a few extra cranks than normal to start but that issue disappeared on its own. No check engine light was ever set due to this. oh this issue was BEFORE the radiator was installed.

One more question does this OBDI CEL system store "pending codes" like the OBD II system does (no light for very rare non critical faults?


Again mike thanks so much for trying to help me.

 

On the Accord a solid CEL with the SCS connector jumpered = no stored ECU codes.

You say that you are having a no start issue..... Have you checked for spark or fuel?

The CEL will not show any codes if there is an issue with the ignition/starting circuit, ignition coil, ignitor (ICM), distributor cap, rotor, spark plug wires or spark plugs. Could also be a fuel pressure issue...no code for that ether.

 

@ Ghost....

The CEL lamp stays lit solid even WITHOUT the jumper in place when you turn the key to accessories position.

I definitely noticed that when I first tried to start the vehicle I could swear that I could NOT hear the relay click and the slight whine of the fuel pump priming for a couple of seconds like it normally does.

I'm going to check the ECU fuse underneath the hood as well.

In our cars that fuse is in the under the hood relay/fuse box correct?

Trying to do the easiest things first.. have no testing tools handy.

I'll get back to you guys tomorrow with additional infomation.

 

That could be anything from a cold start issue, main relay condensation on contacts, or who knows what.
Yes it does. If there was an intermittent fault the CEL light will come on and go off when the fault goes away. This lets you know if a particular device has fallen out of expected threshold.
The light will stay on if there is a hard fault where a component has failed or become disconnected from teh system when the car is 'ON'. But these codes are retrievable when the blue wire is jumped.

Verify that the memory fuse is not blown.
If that is the case when turning the car on the device may be at fault, but when you turn the car off and back on to check for codes(due to memory loss) the ECU will not 'remember' the problem.

 

Mike:

Thanks for all your information...excellent. I guess you are as obsessed with these cd5s as I am. LOL I've been following your other thread about the 95 cd5 you just picked up. Love reading other folks stories about restoring their finds to good condition.

I got up the courage to remove the Main Fuel Relay from the car and take it apart to inspect the solder joints. I found ONE suspect joint the others looked pretty good to me, used a mag loop to closely look for cracks..

I got out the soldering iron and proceeded to resolder the joint.

I did notice something else, there were a few solder joints that looked ok but there were dark brown rings around the joint most others looked perfect, is this anything to be concerned about?

I put the relay back together and reinstalled it.

Turned the car to acc and viola the cel lamp turned on for two seconds and then went out, car started as though nothing ever happened.

I've let the car run and shut off and restarted a dozen times now and no sign of any problem.

One more question..should i attempt to rejumper the service port to see if any codes were stored from the problem or just leave well enough alone.

Why didn't the ECM CEL flash a code for a failed main relay unit????

 

They are understated, there are probably only three main things that go wrong with these cars. Main relay, wheel bearings @100K, and that punks steal them. Otherwise they are a pretty damn fun vehicle. The coupe is nice and has better seating, but the 'new' sedan is just so much more fun to throw around. I've spooked a few unsuspecting assclowns on the road with it.
It is probably just crud accumulated on the board where the flux pooled, or possible from where condensation pooled and crud is jut left behind. If the board itself, or components, are not showing any signs of overheating or burning I wouldn't worry about it.
Woot on then.
AFAIK the ECU nor the rest of the system is on these cars is designed to monitor Main relay functionality. If the Main relay does not work, it does not work, it is simply a relay and IIRC there is nothing monitoring it. As far as the ECU knows, you simply have not turned the car 'ON' when the relay fails.