P0622
P0622-GENERATOR FIELD CONTROL CIRCUIT/OPEN
For a complete wiring diagram, refer to the Wiring Information. Electrical Diagrams
- When Monitored:
With the engine running, battery voltage greater than 10.4 volts, and the generator control active.
- Set Condition:
The Powertrain Control Module (PCM) detects an open or shorted condition in the Generator Control circuit. One trip fault.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
1. DTC IS ACTIVE
1. Turn the ignition on.
2. Using a scan tool, clear DTCs in the PCM.
3. Start the engine and allow it to reach operating temperature.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hand near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in possible serious or fatal injury.
4. Increase the engine speed by pressing the accelerator pedal. Do not exceed 3500 rpm.
5. Using a scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To 2
No
- Refer to the CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. Checking for an Intermittent DTC.
2. (A804) GEN SENSE CIRCUIT OPEN OR HIGH RESISTANCE
CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install the PCM Pinout Box 8815 to perform diagnosis.
1. Turn the ignition off.
2. Disconnect the Generator connector.
3. Disconnect the C1 and C2 PCM harness connectors.
4. Measure the resistance of the (A804) Gen Sense circuit between the Generator harness connector and the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?
Yes
- Go To 3
No
- Repair the (A804) Gen Sense circuit for an open circuit or high resistance.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.
3. (K20) GEN FIELD CONTROL CIRCUIT SHORTED TO VOLTAGE
1. Turn the ignition on.
2. 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 PCM VERIFICATION TEST. PCM Verification Test.
No
- Go To 4
4. (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 above 100 ohms?
Yes
- Go To 5
No
- Repair the (K20) Gen Field Control circuit for a short to ground.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.
5. (K20) GEN FIELD CONTROL CIRCUIT OPEN OR HIGH RESISTANCE
CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install the PCM Pinout Box 8815 to perform diagnosis.
1. Measure the resistance of the (K20) Gen Field Control circuit between the Generator harness connector and the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?
Yes
- Go To 6
No
- Repair the (K20) Gen Field Control circuit for an open circuit or high resistance.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.
6. GENERATOR
1. Connect the PCM connector.
2. Turn the ignition on.
3. Connect a 12-volt test light between the (A804) Gen Sense circuit and the (K20) Gen Field Control circuit in the Generator harness connector.
4. Using a scan tool, actuate the Alternator Field Control State.
NOTE: The voltage supplied to the solenoid circuit during the actuation will be less than battery voltage. The test light should be illuminated, but not as bright as a direct connection to the battery.
Is the test light illuminated during the actuation?
Yes
- Replace the Generator.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.
No
- Go To 7
7. 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. Search for any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.
No
- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM VERIFICATION TEST. PCM Verification Test.