Finding the ECU error codes
 

This comes from my little Civic notebook on my PC too.
All this info I gathered some time ago, glad to put it to good use now!

Here is how you get the ECU to spit out its error codes-

Locate the ECU under the carpet in the passenger foot well.
Find the red LED in the center of the ECU.
Turn the ignition to ON. The red LED should flash once when this happens to indicate that the ECU has power.
If there are no further flashes then there are no error codes.
If there are further flashes then there are one or more error codes.

Thanks again for this great info.
Is this the same on all civic years and models, or just specific to one civic?

I imagine most of them are similar if not the same.

This is true for 85-91 civics i believe...92 on up are different..

How does one find the error codes on the newer cars?
Perhaps we need a sticky on this

There is the paper clip check. Turn the ignition on and off 3 or four times and the cel should flash giving you the code(not sure if it works on civics but the neons i work on work like that).

To be honest I never check the codes.
How accurate are they in really diagnosing the problem?

All they do is give you a close guess really. It will not pin point the error but will lead you in the right direction most of the time from my experience.

Or the wrong one in my case sometimes :p
Sometimes something is wrong that sets off a code, but its something else wrong down the chain thats the real problem - makes it hard to find.

Thats a quicker and probably easier to follow description than mine, thanks for that ;)

On 92-95 civic there are two plugs above the ecu (in a green soft plastic holder) the one with two pins can be jumpered with a paper clip or just a piece of wire with the engine running or stopped after the cel comes on. It will start to flash codes using the cel . one long flash followed by four short flashes is code 14. two long and one short is code 21, two short is code 2 and one long is code 10. that is how it is read by the flashes. once codes flash it will give all codes that it has at that time(separated by about 2 second intervals) then stop for about 4 second and the repeat all codes over and over until you remove the jumper.

I wonderd why this was called the paper clip test. God to know. I always tried to see how to get in the machine, yes the little computer does make mistakes but if they are tied into the rest of the car operation it might be a sympton of something else going wrong.

remember Murphy;'s law: a $600 computer circuit "brain" will blow its charge and burn out to protect a $15 fuse.

Re: Finding the ECU error codes
 

hay i've tried all of this and still nothing I don't have a an "led" on the ecm and the check engine light just stays on.
the problem Im have'n is no start. I have fuel weak spark and compression. Ive put in 2 different distributors and still no dice. all fuses are good battery is good , grounds ......WTF....... help...
Mike

Re: Finding the ECU error codes
 

can anyone help get my radio code please. had battery off and cant get it anywhere all i have is the serial no 30006922 is a y reg civic if anyone can help u can email me at craw76@googlemail.com

Re: Finding the ECU error codes
 

i think this is a bit different on later models. have a 95 civic which i got some years back and while using this step to check the error codes it did not show. finally had to show it to the mechanic for getting the proper work done. although overall a reliable car that week was a bit off as several things went off at the same time. hope it does not bother again.

Re: Finding the ECU error codes
 

my car has had problems starting for a while. i have a '91 civic and it turns over, just doesn't start. the light blinks 4 times, then after blinks 8. does anyone know what error code this may be?

Re: Finding the ECU error codes
 

Just go get the code read at autozone or where ever.

Re: Finding the ECU error codes
 

it's free right?
forgive me if someone posted that it is in this thread before.:_please:

Re: Finding the ECU error codes
 

Ya its free.