The sensor is used to calibrate the signal from the engine speed/timing sensor. The sensor eliminates any mechanical errors.
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| Illustration 1 | g01214321 |
Typical schematic | |
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| Illustration 2 | g01228872 |
P1 ECM connector (P1-5) Digital return (P1-13) Secondary engine speed/timing signal (P1-33) Primary engine speed/timing signal (P1-40) Engine timing calibration − (P1-41) Engine timing calibration + (P1-43) +12.5 V supply | |
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| Illustration 3 | g01287869 |
Typical example Location of the timing calibration probe (typical right side engine view) (1) Timing calibration sensor | |
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| Illustration 4 | g01285750 |
Location of ECM connectors | |
Test Step 1. Inspect Electrical Connectors and Wiring
- Turn the "main disconnect switch (MDS)" to the OFF position.
- Thoroughly inspect the J1/P1 ECM connector and the J2/P2 ECM connector. Inspect all of the connectors that are associated with the circuit.
Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
- Perform a 45 N (10 lb) pull test on each of the wires in the ECM connectors that are associated with the circuit.
- Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
- Check the harness and wiring for abrasion and for pinch points from the sensors back to the ECM.
Expected Result:
All connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion and of pinch points.
Results:
- OK - The harness and connectors appear to be OK. Proceed to Test Step 2.
- Not OK - There is a problem with the connectors and/or wiring.
Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.
STOP
Test Step 2. Check for a Short Circuit and/or an Open Circuit
- Disconnect the connector for the timing calibration sensor.
- Measure the resistance between terminal 1 and terminal 2 on the sensor side of the connector.
Expected Result:
The resistance is between 110 to 200 Ohms.
Results:
- OK - The resistance is between 110 to 200 Ohms. Proceed to Test Step 3.
- Not OK - The resistance is not between 110 to 200 Ohms. The sensor is internally shorted or open.
Repair: Replace the sensor.
STOP
Test Step 3. Check for a Short Circuit in the Wiring Harness
- Disconnect ECM connectors J1/P1 and J2/P2.
- Measure the resistance between P1-40 and every terminal on ECM connectors P1 and P2.
- Measure the resistance between P1-40 and engine ground.
- Measure the resistance between P1-41 and every terminal on ECM connectors P1 and P2.
- Measure the resistance between P1-41 and engine ground.
Expected Result:
The resistance measurement indicates an open circuit for each measurement.
Results:
- OK - The resistance measurement indicates an open circuit for each measurement. Proceed to Test Step 4.
- Not OK - The resistance measurement does not indicate an open circuit for each measurement. There is a short circuit.
Repair: Repair the connectors or wiring and/or replace the connectors and wiring.
STOP
Test Step 4. Check for an Open Circuit in the Harness
- Use a suitable piece of wire to create a short between P1-40 and P1-41.
- Measure the resistance between terminal 1 and terminal 2 on the ECM side of the connector for the timing calibration sensor.
Expected Result:
The resistance measurement indicates a short circuit.
Results:
- OK - The resistance measurement indicates a short circuit.
Repair: Return all wiring to the original configuration. Calibrate the engine speed/timing sensor. Refer to Troubleshooting, "Engine Speed/Timing Sensor - Calibrate".
STOP
- Not OK - The resistance measurement does not indicate a short circuit. There is an open circuit in the harness or connectors.
Repair: Repair the connectors and wiring and/or replace the connectors and wiring.
STOP