P0622 GENERATOR FIELD NOT SWITCHING PROPERLY
When Monitored and Set Condition:
When Monitored: When the ignition is on.
Set Condition: The feedback signal does not match the commanded signal for the voltage regulator.
- OPEN DRIVER CIRCUIT
- GEN SOURCE SHORTED TO BATTERY NEGATIVE
- (K20) FIELD DRIVER CIRCUIT SHORTED TO VOLTAGE
- GEN SOURCE OPEN
Turn the ignition off. Disconnect the Generator field harness connector. Check connectors - Clean/repair as necessary. Measure the resistance between the generator field terminals. Is the resistance between.5 and 15 Ohms?
Yes --> Go To 2
No --> Replace the Generator.
Disconnect the ECM harness connectors. Check connectors - Clean/repair as necessary. Measure the resistance of the generator driver wire between the generator harness connector and the ECM harness connector. Is the resistance less than 10 ohms.
Yes --> Go To 3
No --> Repair the open driver circuit.
Measure the resistance of the generator source circuit between the generator harness connector and battery negative. Is the resistance less than 10 ohms.
Yes --> Repair the Gen source shorted to Battery negative.
No --> Go To 4
Measure the voltage between the (K20) generator field driver circuit in the generator harness connector and battery negative. Is the voltage greater than 1 volt?
Yes --> Repair the (K20) Generator field driver circuit shorted to voltage.
No --> Go To 5
Measure voltage of the Gen source circuit at the generator harness connector. Is voltage within one volt of battery voltage?
Yes --> Replace the ECM.
No --> Repair the open or high resistance of Gen source circuit.