P0622

P0622-GENERATOR FIELD CONTROL CIRCUIT





For a complete wiring diagram, refer to the Wiring Information.

- When Monitored:
With the engine running and battery voltage greater than 10.4 volts.

- Set Condition:
The Powertrain Control Module (PCM) detects that the actual state of the generator field control does not match the intended state.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. DTC IS ACTIVE
1. Start the engine and allow it to reach normal operating temperature.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.

2. With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.

2. (K20) GEN FIELD CONTROL CIRCUIT SHORTED TO VOLTAGE




1. Turn the ignition off.
2. Disconnect the Generator harness connector.
3. Disconnect the Powertrain Control Module (PCM) C2 harness connector.
4. Turn the ignition on.
5. Measure the voltage of the (K20) Gen Field Control circuit in the Generator harness connector.

Is there any voltage present?

Yes

- Repair the (K20) Gen Field Control circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 3

3. (K20) GEN FIELD CONTROL CIRCUIT SHORTED TO GROUND




1. Turn the ignition off.
2. Measure the resistance between ground and the (K20) Gen Field Control circuit in the Generator harness connector.

Is the resistance below 100 Ohms?

Yes

- Repair the (K20) Gen Field Control circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 4

4. (K20) GEN FIELD CONTROL CIRCUIT OPEN OR HIGH RESISTANCE




1. Measure the resistance of the (K20) Gen Field Control circuit between the Generator harness connector and the PCM C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the (K20) Gen Field Control circuit for an open circuit or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

5. GENERATOR




1. Connect the Powertrain Control Module (PCM) C2 harness connector.
2. Turn the ignition on.
3. With the scan tool, actuate the Generator field control to the ON (100%) position.
4. Using a 12-volt test light connected to ground, check the (K20) Gen Field Control circuit in the Generator harness connector.

NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.

5. With the scan tool, actuate the Generator field control to the OFF (0%) position.
6. Using a 12-volt test light connected to ground, check the (K20) Gen Field Control circuit in the Generator harness connector.

NOTE: The test light should not be illuminated.

Is the test light illuminated and bright with the actuation ON (100%) and not illuminated with the actuation OFF (0%)?

Yes

- Replace the Generator. Generator - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 6

6. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Generator and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Replace and program the Powertrain Control Module (PCM). Powertrain Control Module - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.