Bad ECM on 92?
Thread Starter
Intermediate
Joined: Mar 2002
Posts: 48
Likes: 0
From: Naugatuck CT
Bad ECM on 92?
92 convertible was running fine Mon-Tue-Wed. I started it Thur morning and SERVICE ENGINE light on. Speedo wouldn't read anything but zero. Engine hesitates on accel. Shorted A-B and got only SYS flashes. Shorted A-G and got codes: with small '1': C41, H41, H72, ---, with small '4': Err, then with small '9' got H65, H72, --- then small '1.0' I think this means that my electronic spark timing has a bad connection or bad box, or my ECM needs replacing. Why 'Err'? Any suggestions?
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
oooh... "ERR" means that the CCM cannot communicate with the ECM.
That is not good.
Now, when you jump A-B, the SES should flash... SYS flashes sound like an error.
The C41 (C=current) means that the CCM has lost contact with the ECM.
Read this: C4 Guru - Pulling CCM Codes 1992-1993
That is not good.
Now, when you jump A-B, the SES should flash... SYS flashes sound like an error.
The C41 (C=current) means that the CCM has lost contact with the ECM.
Read this: C4 Guru - Pulling CCM Codes 1992-1993
Thread Starter
Intermediate
Joined: Mar 2002
Posts: 48
Likes: 0
From: Naugatuck CT
So . . . I did the in-depth code pulling on my 92 and everything in sec 1.x looked consistent with earlier codes (above), detail troubleshooting found nothing wrong. Likewise section 9.x looked same for 9.1 and 9.7. 4.7 showed the end code '- - -' but 4.1 just showed 'Err'. I disconnected the batt, disconnected and pulled the ECM and pulled out the PROM, then reseated it. When I put it back together, I got C12 to start sec 1.x, but still got 'Err' at 4.1. Is the ECM definitely bad?
Safety Car
Joined: Feb 1999
Posts: 3,504
Likes: 4
From: Mexico Beach FL
The problem you mention is usually a defective ECM on vehicles up to the ECM change in '94 -- the '94 and up do not seem to have as many ECM problems.
This problem is hard to pin down between the ECM and CCM while trouble-shooting, but the ECM is usually the culprit.
Tom Piper
This problem is hard to pin down between the ECM and CCM while trouble-shooting, but the ECM is usually the culprit.
Tom Piper
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
I had the ECM go out on my 92. I could be driving it an basically every gauge would freeze where it was, including the tach. Every idiot light in the car would come on. It would still run but it was most certainly in "limp home" mode, which is far less than optimal with my modifications. It had a very bad stumble on acceleration, etc. It would do that to me and then if I hit a big enough bump it would go away. I replaced the ECM a few years ago and haven't had any trouble since.
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From: Canton GA
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Originally Posted by stanandsue
thanks - I'll start looking for an ECM
Le Mans Master
Joined: Sep 2000
Posts: 6,654
Likes: 145
From: Willow Glen, California......................"But... Chunks is our dog!"
Originally Posted by bogus
oooh... "ERR" means that the CCM cannot communicate with the ECM.
That is not good.
Now, when you jump A-B, the SES should flash... SYS flashes sound like an error.
The C41 (C=current) means that the CCM has lost contact with the ECM.
Read this: C4 Guru - Pulling CCM Codes 1992-1993
That is not good.
Now, when you jump A-B, the SES should flash... SYS flashes sound like an error.
The C41 (C=current) means that the CCM has lost contact with the ECM.
Read this: C4 Guru - Pulling CCM Codes 1992-1993
Le Mans Master
Joined: Sep 2000
Posts: 6,654
Likes: 145
From: Willow Glen, California......................"But... Chunks is our dog!"
Originally Posted by bogus
that tells me there may be a harness problem that needs to be chased down.
That's what I figured (was afraid of).
Nice CCM Code reading write-up BTW!
Safety Car
Joined: Feb 1999
Posts: 3,504
Likes: 4
From: Mexico Beach FL
Originally Posted by test
Does anyone know why the word "SYS" would flash on the digital display?
The SYS indicates there is a problem detected by the CCM.
Tom Piper