Conditions Which Generate This Code:
The Engine Control Module (ECM) detects the following conditions:
• A timing calibration has been successfully completed.
• The primary engine speed/timing sensor and the secondary engine speed/timing sensor are off by more than 3 degrees.
System Response:
This code will not be logged. The check engine lamp will illuminate while this diagnostic code is
active. The ECM will use the default timing.
Possible Performance Effect:
The engine may run rough when this code is active.
Troubleshooting:
Test Step 1. Engine Overspeed
A. Check the ECM for indications of an engine overspeed.
B. If there are indications of an engine overspeed, check the cluster gear for proper alignment.
Also check the cluster gear for damage. Refer to Testing and Adjusting, “Gear Group (Front) – Time”.
Expected Result:
The cluster gear is properly aligned and there is no damage to the cluster gear.
Results:
• OK – Proceed to Test Step 2.
• Not OK – The cluster gear is not aligned correctly or there is damage to the cluster gear.
Repair: Align the cluster gear or repair the cluster gear.
Run the engine until the engine reaches operating temperature.
Verify that the repair eliminates the problem.
STOP.
Test Step 2. Accident
A. Determine whether the vehicle has been involved in an accident.
If the vehicle was involved in an accident, then the cluster gear may have been damaged.
B. Check the cluster gear for damage.
Expected Result:
The cluster gear is not damaged.
Results:
• OK – Proceed to Test Step 3.
• Not OK – There is damage to the cluster gear.
Repair: Repair the cluster gear.
Run the engine until the engine reaches operating temperature.
Verify that the repair eliminates the problem.
STOP.
Test Step 3. Cylinder Head
A. Determine whether the cylinder head was removed.
B. If the cylinder head was removed, the backlash for the camshaft may be out of the specification.
C. Check the backlash for the camshaft. Refer to
Testing and Adjusting, “Gear Group (Front) – Time”.
Expected Result:
The backlash for the camshaft is within specifications.
Results:
• OK – Proceed to Test Step 4.
• Not OK – The backlash for the camshaft is not within specifications.
Repair: Adjust the backlash for the camshaft.
Refer to Testing and Adjusting, “Gear Group (Front) – Time”.
Run the engine until the engine reaches operating temperature.
Verify that the repair eliminates the problem.
STOP.
Test Step 4. Engine Speed/Timing Sensors
A. Check the engine speed/timing sensors for proper installation. The engine speed/timing
sensors can not be interchanged.
B. Verify that the sensor wires are connected properly. Refer to the electrical schematic for proper wiring. Make sure that the positive terminal on the ECM is connected to the positive terminal on the engine speed/timing sensors.
Also, make sure that the negative terminal on the ECM is connected to the negative terminal on the engine speed/timing sensors.
Expected Result:
The engine speed/timing sensors are properly installed. Also, the engine speed/timing sensors are wired correctly.
Results:
• OK
Repair: Refer to Troubleshooting, “Engine Speed/Timing Sensor Circuit – Test”.
STOP.
• Not OK – There is a problem with the installation or the wiring of the engine speed/timing sensors.
Repair: Install the sensors properly or repair the wiring.
Run the engine until the engine reaches operating temperature.
Verify that the repair eliminates the problem.
STOP.
