Finding the ECU error codes

CG99 · 03-05-2006

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.

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Darth · 03-05-2006

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.

vargasr66 · 05-10-2006

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

TomH · 05-10-2006

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

Tayler · 05-10-2006

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).

anteater · 05-10-2006

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

Tayler · 05-10-2006

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.

GT_1 · 05-11-2006

Or the wrong one in my case sometimes

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.

CG99 · 05-15-2006

Quote:

Originally Posted by Tayler

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).

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

vargasr66 · 05-27-2006

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.

fivespeed · 05-27-2006

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.