Lower Driver Side Cover Removal - 1990 C4
Thread Starter
Cruising
Joined: Sep 2006
Posts: 14
Likes: 0
From: Clovis, California
Lower Driver Side Cover Removal - 1990 C4
1990 C4
OK ... I am trying to get the lower drivers side cover off to get to the CCM (code C41 - lost communication to ECM / also doesn't pull a C12 code) and I can't seem to get it out ... I have it to the point where it hangs down but still seems to be attached somewhere way in the back by the firewall ...
Has anyone done this before ... any ideas?
OK ... I am trying to get the lower drivers side cover off to get to the CCM (code C41 - lost communication to ECM / also doesn't pull a C12 code) and I can't seem to get it out ... I have it to the point where it hangs down but still seems to be attached somewhere way in the back by the firewall ...
Has anyone done this before ... any ideas?
Drifting
Joined: May 2003
Posts: 1,979
Likes: 48
From: Lakeport CA
There is a retainer "clip" back between my clutch/brake pedal. A bolt points straight down & has a flat round spring steel disk that unscrews, to install you just push it up over the threads. At least that is how mine is held. There is also the wiring for the courtesy light which can interfere w/ removal.
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
On the diagnostic connector, if you short pin A to pin B and turn the ignition on, the service engine soon light should blink code 12 three times, any ECM error codes 3 times then 12 three times.
If code 12 doesn't display, the ECM is probably bad, the Eprom could be bad or there is no power to the ECM.
From your description it appears, you shorted pin G to A and turned the ignition on and saw Module 1 CCM code 41 displayed on the Dash Cluster. That indicates the CCM is probably good but can't communicate with the ECM.
[F|E|D|C|B|A]
[G|H|J|K|L|M]
If code 12 doesn't display, the ECM is probably bad, the Eprom could be bad or there is no power to the ECM.
From your description it appears, you shorted pin G to A and turned the ignition on and saw Module 1 CCM code 41 displayed on the Dash Cluster. That indicates the CCM is probably good but can't communicate with the ECM.
[F|E|D|C|B|A]
[G|H|J|K|L|M]
Last edited by Hooked on Vettes; Nov 19, 2006 at 04:15 PM.
Thread Starter
Cruising
Joined: Sep 2006
Posts: 14
Likes: 0
From: Clovis, California
Thanks to both of you ... i just got this car a month ago (my first Corvette - loaded and only 35,000 miles - loaded seems to mean lots of electric stuff to go bad 
) and was fixing all the little things that were wrong and this was the last thing that I needed to do (had the dash torn apart for the radio and radio receiver ... got that fixed) and then thought I would go a little further to make sure all the CCM cables were connected correctly.
I think you are right though ... it is probably the ECM (looks like it was a rebuilt one). When I hook up my OBD-I code reader it can't communicate with the ECM (no serial data communications).
) and was fixing all the little things that were wrong and this was the last thing that I needed to do (had the dash torn apart for the radio and radio receiver ... got that fixed) and then thought I would go a little further to make sure all the CCM cables were connected correctly.I think you are right though ... it is probably the ECM (looks like it was a rebuilt one). When I hook up my OBD-I code reader it can't communicate with the ECM (no serial data communications).
