P0621-GENERATOR LAMP/L-TERMINAL CONTROL CIRCUIT OPEN
For a complete wiring diagram Refer to Section 8W
- When Monitored:
With the ignition on.
- Set Condition:
The ECM detects an open or short to ground on the Charge Indicator Signal circuit.
| Possible Causes |
| INTERMITTENT DTC |
| (G329) CHARGE INDICATOR SIGNAL CIRCUIT SHORTED TO GROUND |
| (G329) CHARGE INDICATOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE |
| GENERATOR |
| ENGINE CONTROL MODULE (ECM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
Diagnostic Test
1. DTC IS ACTIVEIgnition on, engine not running.
With the scan tool, clear DTCs in the Engine Control Module (ECM).
Test drive the vehicle
With the 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. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
2. (G329) CHARGE INDICATOR SIGNAL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the Generator harness connector.
Disconnect the Engine Control Module (ECM) harness connector.
Measure the resistance between ground and the (G329) Charge Indicator Signal circuit in the Generator harness connector.
Is the resistance above 1000 ohms?
Yes
- Go to 3
No
- Repair the (G329) Charge Indicator Signal circuit for a short to ground.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
3. (G329) CHARGE INDICATOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
Measure the resistance of the (G329) Charge Indicator Signal circuit between the Generator harness connector and the Engine Control Module (ECM) harness connector.
Is the resistance below 10.0 ohms?
Yes
- Go to 4
No
- Repair the (G329) Charge Indicator Signal circuit for an open circuit or high resistance.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
4. GENERATOR
Turn the ignition off.
Replace the Generator.
With the scan tool, Clear DTCs.
Test drive the vehicle.
With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go to 5
No
- Test complete
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
5. ENGINE CONTROL MODULE (ECM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Generator and the Engine Control Module (ECM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Refer to any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Replace the Engine Control Module (ECM) in accordance with the Service Information.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)