ENG: Diagnose a Check Engine Light and S/D4 errors.

[phunkatek]

Eventhough my car has never given me a CEL , today I decided to pull codes (stored codes) for the heck of it. I jumped the wires on the blue connector and turned the switch to 2. The CEL came on but never went out even after I waited a minute or two. I then started the car (jumper still on) and the same thing happenend.

What does that mean?

ANYONE WONDERING WHY THE CEL LIGHT STAYS ON AFTER JUMPING THE CONNECTOR:

if your CEL light stays on after you jumper the connector, you'll have to reset the ECU and run the car to let it get the codes again. If Mike up there is right, it may mean you have a faulty ECU.
And remember, it might actually be your D4 light that flashes instead of the CEL (it was for me). I'm not sure if this is different per vehicle year or just because of this situation.
At the bottom of the first post on this topic, aero actually gives the instructions to reset the ECU:

Resetting ECU

1. Disconnect Negative battery terminal (never only take off the positive, cuz it can kill the battery when it grounds all the power out, if left for a while)

2. Look in the Underhood fuse box, find the "Hazard" Fuse [Edit: or BACK UP Fuse] . Pull it out.

3. Let the car sit for 10-15 minutes

4. Reattach neg battery terminal and put fuse back in

5. Restart car w/nothing on (radio, lights, a/c) and just let it run for a few minutes.

6. Turn off, and then it should be good to go.

I had this same problem too and kind of stumbled across the solution. In my shop manual I was looking at a troubleshooting flowchart for the throttle angle sensor where it says that you need to remove the BACK UP fuse in the under-hood relay for 10secs to reset the ECU b4 jumping the connector. I did this, but after I then jumped the connector I still didn't see any flashing CEL light. Well, on the flowchart it sez if its not throwin any codes then it could be an intermittent failure and/or a test drive may be necessary, so I drove the car around for a few mins and then jumnped it again and whala! My D4 light started blinking.

I always thought I was supposed to be looking at the yellow CEL light to blink but I guess it's different when you are getting a Solid CEL light cuz if you have to test drive it, it must mean there were no codes stored.
I tried a couple different things before stumbling on the right process. Car off, remove fuse... car off remove fuse and neg batt cable... acc. on remove fuse.. after that when I test drove the car and jumped the connector again I finally got the codes. And FYI, this was on a '92 accord LX wagon.

[YellowCord]

I have a question? when i check the CEL, I dont need to connect the those 2 wire together. I just flip out the carpet and saw the ECU, then i put my key to on, which is Number 2. There's a red light on the ECU which give out the code, INSTEAD of give out code on instrument, so do anybody know about this?

[phunkatek]

yeah i think that might be for OBD0 accords- what year is your accord? Is it earlier than '92? I read that OBD0 accords have a little window on the ECU that displays error codes also.

It looks like how the ECU error codes are displayed might be a little different according to whether your obd0 (-91), obd1 (92-95), or obd2 (95+) but they all still have a service connector so its the same general procedure.

[Maple50175]

hey i have this cel code 8 TDC - top dead centre sensor


Why?

[WilliamW]

Originally Posted by SuddenCb7 I beleive any vehicle 97 and after is obd2.

It's actually 1996 and up. They started in 96 but ALL cars in 97 had to be OBDII. Dont take me for truth but It's just what I was told. But I do know they had OBDII in 96.


I have a code 15

[aznpnoyracer]

does the 92 accord dx have one of these blue connectors? cuzz I looked at mine and I couldnt find one.

[UrDoneSRH]

im throwning this code:

41 Primary oxygen sensor heater

i dont know what it means can someone point me in the right direction?

[d112crzy]

one of your o2 sensor wires is fucked up.

take a look at your o2 sensor. right where the wires come from, check to see if wires are exposed or messed up. you'll prolly have to replace it.

replacing an o2 sensor is as easy as taking off a bolt.

[UrDoneSRH]

ok thats what i thought it was, when i was installing my headers, my friend dropped a bolt down the downpipe so we had to take that shit off, and in the process of removing the downpipe the o2 sensor wires got yanked outta the harness, i re-pinned them, maybe they came loose or something. im going to try to just reset the CEL before i jack the car up and everything. thanks for the help.

[rlyons]

I am getting a code 43 (fuel supply system), what is it telling me?

[93EXaesthetic]

thanks for posting this.. i got a CEL i cant figure out.. and oil in my coolant

[socal_cb7]

Thanks man, I just pulled out my codes and it gave me 1, and 43...
my question is code 1 is O2A-Oxygen Sensor #1 would that be this one?


and for code 43 - Fuel supply system, this means that I have to change my entire fuel system or just the fuel pump?

Thanks in advance...

[d112crzy]

Usually, those codes come in pairs.

Replace your oxygen sensor first, then see if code 43 persists. Replacing the oxygen sensor usually gets rid of that code.

[johndenver120]

is this the same in all hondas? or is obd2 different?

my bro has a 6gen wich i need to check the code

[accordaffair]

I suspect it will be different for your 6th gen