GM OBD Trouble Code 99
Invalid PCM program
If the PCM detects a problem with its software code 99 will be set.
Fault Code Description
- 99 - Invalid PCM program
Symptoms
- Engine may not start
Common Problems
- PCM should be reprogrammed in possible
Related Questions
See what others have asked about this, or visit the Questions page to ask your own question.
Replaced the ecm , changed the the spark plugs and spark plug wires, change the cam sensors, why is the check engine...
Dont work checked fuses and relays good