My Z car (standard 4 speed ) doesn't idle down when at a stop sign, and occasionally the engine revs to 3000 RPMs when sitting at a stop sign, any suggestions?
The Powertrain Control Module (PCM) monitors the charging system for changes in the output voltage. The PCM will set the code P0502 when the output voltage is out of factory specifications. So it may be overcharging or undercharging.
Code P2502 Possible causes
- Faulty Generator (Alternator)
- Generator harness is open or shorted
- Generator circuit poor electrical connection
- Faulty Powertrain Control Module (PCM)