Codes C12, H64, and H72 ???
Race Director
Joined: Aug 2003
Posts: 13,421
Likes: 8
From: Lake Mary Florida
C's are current DTCs and H's are historicals.
The 12 indicates diagnostics is operational and there are no DTCs if that is all that shows up, i.e., beginning and end.
64 I don't have a listing for that one, might have something to do with PKE. Its historical.
72 is LCD Dimming output circuit open or shorted to ground. Again it is historical.
Use the Fuel/Info to step .7 of each and hold Eng/Met until --- to clear those codes. Run it for a while and after a few ignition cycles you could check again. If you only get the 12 your ok.
The 12 indicates diagnostics is operational and there are no DTCs if that is all that shows up, i.e., beginning and end.
64 I don't have a listing for that one, might have something to do with PKE. Its historical.
72 is LCD Dimming output circuit open or shorted to ground. Again it is historical.
Use the Fuel/Info to step .7 of each and hold Eng/Met until --- to clear those codes. Run it for a while and after a few ignition cycles you could check again. If you only get the 12 your ok.
Melting Slicks
Joined: Apr 2003
Posts: 2,150
Likes: 6
From: NS
C12 is normal. No reference pulse (engine not running).
Not sure if the '94 is different but this is what my '95 manual says for the PCM codes:
H64 - PCM - Right O2 - Lean exhaust. Since it's a "H"istorical code it's probably nothing to worry about unless it keep coming back after you reset it.
H72 - PCM - Loss of vehicle speed sensor. Another historical code, no problem unless it comes back after a reset.
Not sure if the '94 is different but this is what my '95 manual says for the PCM codes:
H64 - PCM - Right O2 - Lean exhaust. Since it's a "H"istorical code it's probably nothing to worry about unless it keep coming back after you reset it.
H72 - PCM - Loss of vehicle speed sensor. Another historical code, no problem unless it comes back after a reset.
Advanced
Joined: May 2003
Posts: 59
Likes: 0
From: Ossian IN
You stick in the paper clip and turn on the ignition. The LCD starts at section one, the Chassis Control Module, and displays C12 to let you know the system is working. Then "---" if there are no more stored DTCs. Next, section 4, Powertrain Control Module, displays "---" if there are no stored DTCs. Next is section 9, ABS / ASR. Again "---" if there are no stored DTCs. Last is section A, Diagnostic and Energy Reserve Module (air bags) also showing "---" for no stored DTCs. The system then shows "1.0" and waits for a command.
In each section the code number means something different. DTC 72 in section one means LCD dimming output circuit open or shorted while DTC 72 in section 4 means vehicle speed sensor loss.
"C" means a current code while "H" means history. But you may get an "H" designation simply because the engine is not running to create the problem. Clear the codes in each section and see if they reset after a short drive. This will tell you if they are still occurring.
Let me know which trouble codes you are getting in each section and I'll let you know what they mean.
Rebuilder
In each section the code number means something different. DTC 72 in section one means LCD dimming output circuit open or shorted while DTC 72 in section 4 means vehicle speed sensor loss.
"C" means a current code while "H" means history. But you may get an "H" designation simply because the engine is not running to create the problem. Clear the codes in each section and see if they reset after a short drive. This will tell you if they are still occurring.
Let me know which trouble codes you are getting in each section and I'll let you know what they mean.
Rebuilder
