P0622 Generator Field Not Switching Properly

SYMPTOM
P-0622 GENERATOR FIELD NOT SWITCHING PROPERLY

WHEN MONITORED
With the ignition key on and the engine running.

SET CONDITION
When the PCM tries to regulate the generator field with no result during monitoring.

POSSIBLE CAUSES
- Generator field source (+) circuit open
- Generator wiring harness intermittent defect
- Generator wiring harness observable defect
- Generator field driver circuit defective
- Powertrain control module defective
- Generator field driver circuit open
- Generator field driver circuit shorted to ground