DTC P0622: Generator Field Not Switching Properly: Notes
NOTE:
To identify field terminals, measure voltage between ground and each field terminal with engine running. Positive field terminal voltage should be 12.5-14.5 volts. Negative field terminal voltage should be 3-8 volts less than battery voltage.
Diagnostic Trouble Code (DTC) is set when Powertrain Control Module (PCM) attempts to regulate generator field with no result during monitoring. Possible causes are generator field resistance more than 5 ohms, open generator field driver circuit, generator field driver circuit shorted to ground, defective generator or PCM.