Flashing SES Light
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 41
Likes: 40
From: Northeast PA
Flashing SES Light
Please help! After putting only a few miles on my 89 this spring, the SES light began flashing on the DIC. It will flash fast, then go out for a few minutes, then come on steady, then out again, then start the rapid flashing all over again. I dropped it off to a mechanic to look at and was told the ECM was bad. I replaced the ECM today, and am having the same problem. I tried to pull codes, but am getting nothing, just Code 12. Another wierd thing is that WITHOUT A and B jumped, and the ignition on, car not running, the SES flashes 12. I thought that it should be on steady with the key on, but not running. The "Service Ride Select" is also flashing. Engine ground is good. Any suggestions? Can it be the PROM? Thanks for the help!
Le Mans Master
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
Usually a flashing SES is indication of a fuel system problem. It happened on my son's Lumina, it had a malfunctioning injector. BUT, it threw a code so this may not be the case with your car.
Team Owner
Joined: Jan 2003
Posts: 20,304
Likes: 240
From: Summerland B.C. Canada
Sounds like ECM circuit 451 is shorted to ground. This would cause the ECM to be in "Field Service" mode with engine running and "Diagnostic" mode with ignition on (engine off).
If you pull the 24 pin from back of ECM, you can test for continuity between terminal A9(white/black wire) and ground. If there is continuity, you found the problem, just have to find the short. Maybe it's at the back of ALDL connector ??
If you pull the 24 pin from back of ECM, you can test for continuity between terminal A9(white/black wire) and ground. If there is continuity, you found the problem, just have to find the short. Maybe it's at the back of ALDL connector ??
