No code C12
Thread Starter
Race Director
Joined: Oct 2011
Posts: 16,076
Likes: 816
From: Dallas Texas
2025 C4 of the Year Finalist - Modified
No code C12
I was checking for codes today, and got no C12. I have codes h72 and h74. I belive are the VATS and radio. Back then, I would get code C12 at the beginning every time. Does this mean something is wrong with ECM or PROM?
Car is a 93 lt1
Car is a 93 lt1
Last edited by 1993C4LT1; Jul 31, 2015 at 04:56 PM.
Race Director
Joined: Jan 2000
Posts: 16,872
Likes: 4
From: Owings Mills, MD 21117
You have H = History codes. If you don't have any problems, no trouble lights in the DIC and SYS is not flashing then I would not be concerned. I have a GM Tech 1 with MSC could read and clear the codes for you if you are in the Baltimore, MD area. 
Team Owner
Joined: Oct 2007
Posts: 26,745
Likes: 694
From: PA
you should be fine as stated if no other things are flashing.
Thread Starter
Race Director
Joined: Oct 2011
Posts: 16,076
Likes: 816
From: Dallas Texas
2025 C4 of the Year Finalist - Modified
Ok, thanks a lot guys. Mark, I'm in Dallas. But thanks for the offer! My car feels like it's not running on all 8. Ran perfect yesterday. Starts up weak on cold starts, sometimes it would stall. I pulled two plugs on driver side, one was oil fouled. Think it's due to bad valve stem seals. Very little amount of blue smoke on start up, I'm talking very little. Sometimes I hate this car
And no, there is no SEL light
And no, there is no SEL light
Race Director
Joined: Jan 2000
Posts: 16,872
Likes: 4
From: Owings Mills, MD 21117
Ok, thanks a lot guys. Mark, I'm in Dallas. But thanks for the offer! My car feels like it's not running on all 8. Ran perfect yesterday. Starts up weak on cold starts, sometimes it would stall. I pulled two plugs on driver side, one was oil fouled. Think it's due to bad valve stem seals. Very little amount of blue smoke on start up, I'm talking very little. Sometimes I hate this car And no, there is no SEL light
And no, there is no SEL light
