1993 C4 Engine Problem/Diagnosis
1. Dash lights were dim including hi-low beam indicator.
2, Temp gauge went past high, other gages looked ok.
3. DIC panel - Service ASR light on and was bright, Service ABS light on and bright. Passive key entry was dimly lit or would go off, but when I accelerated it would flash on and off at times.
4. Heater fan was on but none of the heater/a/c buttons would work to change fan speed. This is a C68 Electronic A/C.
5. No power seat or windows working.
6. Engine would rev up, missed a little, probably due to old fuel and would idle.
7. Headlights would not come on. When I did turn them on the engine immediately would start to flutter and quit if I didn't turn them off.
8. Battery was new last year and I charged it before starting.
Not sure how soon I can get someone to help me pull the codes. Car was working fine until I turned the A/C on last year. That is all the info I know of for now.





You can read CCM DTC's by grounding pin G in the ALDL, then turning the key to the on position, the codes will display in the speedometer. (Pin A is ground.)
A. Ground
B. Diagnostic Terminal
C. A.I.R.
D. Service Engine Soon Light
E. Serial Data
F. TCC
G. Fuel Pump
M. Serial Data
• Jumper Pin G of the DLC to ground and turn on ignition. It is the pin to the bottom far left.
• The CCM should automatically display any codes stored.
o CCM is module 1
o ECM is module 4
o ABS/ASE EBTCM is module 9
Each code is displayed for 3 seconds followed by a 1 second pause till the next DTC appears. There is a 3 second pause between modules as well. The end of the list is indicated by --- on the display.
You’re now in manual mode, use the trip/reset button to cycle thru the modules, get to module 9.0. To enter a module press the trip/odo button until 9.1 appears. Then hit the english/metric button to display codes. Continue to hit this button until --- appears; that is all the codes in the module.
The fuel info button will take you backwards on the list.
Thought maybe someone has had similar problem.




