RENR5042-02 139 Troubleshooting Section a. Measure the sensor’s resistance between P2-46 (Secondary engine speed/timing positive) and P2-47 (Secondary engine speed/timing negative). Expected Result: The readings are within the specifications. Results: b. Check for an intermittent open circuit or for a short circuit by moving the harness while you take the resistance measurement. Pull the wires that are directly behind the sensor or shake the wires that are directly behind the sensor. OK The readings are within the specifications. Proceed to Test Step 5. Not OK The readings are not within the specifications. Resistance ........................ 600 to 1800 Ohms Repair:
Perform the following procedure in order to check and install the new sensor: Expected Result: 1. Before you install the new sensor, measure the resistance of the new sensor. The readings are within the specifications. Results: If the new sensor resistance is within the specification, install the new sensor in the engine according to the following procedure: OK – The readings are within the specifications. Neither a short circuit nor an open circuit is indicated. Proceed to Test Step 5. a. Loosen the bolt and remove the bolt that holds the sensor mounting bracket to the engine. Not OK The readings are not within the specifications.
The sensor resistance is not within the acceptable range when the sensor resistance is measured through the engine harness. Proceed to Test Step 4. b. Ensure that one O-ring is installed on the new sensor. Verify that the O-ring is free of damage. Test Step 4. Measure the Resistance of the Sensor c. Seat the sensor and tighten the bolt. A. Disconnect the suspect sensor from the engine harness. If the sensor will not seat, repair the sensor or replace the sensor, as required. Note: Do not remove the sensor from the bracket. B. Thoroughly inspect the sensor’s connectors. Refer to Troubleshooting, “Electrical Connectors - Inspect” for details. d.
Ensure that the sensor is properly oriented and that the harness is secured in the proper location. C. If you are troubleshooting a problem with the primary engine speed/timing sensor, perform the following procedure: 2. Verify that the repair eliminates the problem. a. Measure the sensor’s resistance between J401-2 (Primary engine speed/timing positive) and J401-1 (Primary engine speed/timing negative). STOP. Test Step 5. Install the Bypass Harness for the Engine Speed/Timing Sensors A. Turn the key switch to the OFF position. Resistance ............................. 75 to 230 Ohms B. Disconnect the J2/P2 ECM connector. D.
If you are troubleshooting a problem with the primary engine speed/timing sensor, perform the following procedure: C. Use the following procedure for the primary engine speed/timing sensor: a. Measure the sensor’s resistance between J402-2 (Secondary engine speed/timing positive) and J402-1 (Secondary engine speed/timing negative). a. Fabricate a harness from two wires. The wires must reach between the primary engine speed/timing sensor and the P2 connector. Twisted pair wiring is required. Ensure that the wires have at least one twist per inch. Resistance ........................ 600 to 1800 Ohms b. Connect one wire of the harness between P2-35 and P401-2.