Bad ECM on 92?
Le Mans Master
Joined: Sep 2000
Posts: 6,653
Likes: 141
From: Willow Glen, California......................"But... Chunks is our dog!"
Originally Posted by bogus
sorry for the bad news....
glad you liked the write up!!! We aim to please!!!
glad you liked the write up!!! We aim to please!!!
Now I'm concerned because I don't feel like I've really done anything to fix the problem. So, while it's running, I rap on the ECM with my knuckles. It immediately goes into run-like-crap mode. I run diagnostics and all of the codes are back and the fans are running. While in diag mode, I flipped over the ECM and pushed down on one end of the EPROM. Fans stop. Lift finger, fans start again. Repeat, same thing. While holding my finger on the EPROM, the diags run clean. When I let go, bad news returns. It does this with both ECMs, so I'm thinkin' that my EPROM is hosed.
Where does one buy a new, stock EPROM for a 92?
(sorry for the long story)
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
yes, the ECM is bad. Or, more accurately, there is a bad solder joint on that board.
If you know someone who is good with a soldering iron, it might be worth taking it apart the ECU and checking the internals.
Otherwise, check with The Last Detail, Ecklers, NAPA or Chris May at Superior Chevy (1.800.728.8267), tell him you are a forum member and that I sent ya.
If you know someone who is good with a soldering iron, it might be worth taking it apart the ECU and checking the internals.
Otherwise, check with The Last Detail, Ecklers, NAPA or Chris May at Superior Chevy (1.800.728.8267), tell him you are a forum member and that I sent ya.
Le Mans Master
Joined: Sep 2000
Posts: 6,653
Likes: 141
From: Willow Glen, California......................"But... Chunks is our dog!"
Originally Posted by bogus
yes, the ECM is bad. Or, more accurately, there is a bad solder joint on that board.
If you know someone who is good with a soldering iron, it might be worth taking it apart the ECU and checking the internals.
Otherwise, check with The Last Detail, Ecklers, NAPA or Chris May at Superior Chevy (1.800.728.8267), tell him you are a forum member and that I sent ya.
If you know someone who is good with a soldering iron, it might be worth taking it apart the ECU and checking the internals.
Otherwise, check with The Last Detail, Ecklers, NAPA or Chris May at Superior Chevy (1.800.728.8267), tell him you are a forum member and that I sent ya.
I did buy a new ECM from tld and it's doing the same thing as the old one. I'm 95% convinced that there's a problem with the Memcal/EPROM, but I'll certainly check out the possibility of a bad solder joint, as well.
Drifting
Joined: Mar 2005
Posts: 1,923
Likes: 0
From: GA
Originally Posted by Nimrod
Thanks bogus.
I did buy a new ECM from tld and it's doing the same thing as the old one. I'm 95% convinced that there's a problem with the Memcal/EPROM, but I'll certainly check out the possibility of a bad solder joint, as well.
I did buy a new ECM from tld and it's doing the same thing as the old one. I'm 95% convinced that there's a problem with the Memcal/EPROM, but I'll certainly check out the possibility of a bad solder joint, as well.
Le Mans Master
Joined: Sep 2000
Posts: 6,653
Likes: 141
From: Willow Glen, California......................"But... Chunks is our dog!"
Originally Posted by Morley
The memcal's are just a few chips solidered into a carrier. Get a powerful magnifying glass and check the soliders on all of the chips. Then flip the memcal over and have a look at the female pins on it. You may be able to spot one that is bent out of shape and causing poor contact.
The pins on the white board on the left are a bit loose in the socket. I'll mess with it some more tomorrow.
Thanks again bogus! At least it's not in the harness!
Thread Starter
Intermediate
Joined: Mar 2002
Posts: 48
Likes: 0
From: Naugatuck CT
So the ECM from TLD jumped in price to $225 from $157 because GM just discontinued them. It arrives UPS today, and I'll try it. Hopefully, it will work, but if not, this thread has a lot of good info for me to try next, so thanks a lot.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Originally Posted by Nimrod
Thanks Morley.
The pins on the white board on the left are a bit loose in the socket. I'll mess with it some more tomorrow.
Thanks again bogus! At least it's not in the harness!
The pins on the white board on the left are a bit loose in the socket. I'll mess with it some more tomorrow.
Thanks again bogus! At least it's not in the harness!
If it's just loose, perhaps a touch of superglue or epoxy to reinforce it. I would be real careful soldering in there...
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Thread Starter
Intermediate
Joined: Mar 2002
Posts: 48
Likes: 0
From: Naugatuck CT
It works!!! thanks for the help. the new ECM read C12 in 1.x and --- in 4.x. 9.x still has an H72 data link error that didn't clear with the batt disconnected, but no current codes. It started and ran fine. I don't mind spending the money when it fixes the problem. 
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Originally Posted by stanandsue
It works!!! thanks for the help. the new ECM read C12 in 1.x and --- in 4.x. 9.x still has an H72 data link error that didn't clear with the batt disconnected, but no current codes. It started and ran fine. I don't mind spending the money when it fixes the problem.
Intermediate
Joined: Oct 2004
Posts: 47
Likes: 0
Originally Posted by Tom Piper
The Check Engine light is the indicator that there is a problem detected by the ECM.
The SYS indicates there is a problem detected by the CCM.
Tom Piper
The SYS indicates there is a problem detected by the CCM.
Tom Piper
well, I found out that the flashing SYS meant nothing more than my radio wasn't connected. Now if I can only find out why my replacement bcm is telling me that I have a full tank of gas when I don't
