Illustration 1 | g00565150 |
Note: Ensure that the desired diagnostic code (CID FMI) is on hold. Ensure that the "SERV CODE" indicator is ON. The operator should use the electrical system schematic for the engine that is being serviced to find the connector contact on the Main Display Module that corresponds to the current CID that is shown.
When the Main Display Module recognizes an abnormal sensor signal, the diagnostic code is recorded. The sensor signal is not visible to the Main Display Module's input circuitry. The following conditions are a result of this diagnostic condition: a flashing Alert indicator and Gauge Needle in the warning region. The following examples are possible causes.
- The Fuel Pressure Sensor has a problem.
- The ground circuit of the Fuel Pressure Sensor that is located in the engine harness is open.
- The signal circuit of the Fuel Pressure Sensor is shorted to +Battery. This circuit is located in the engine harness.
- The signal circuit of the Fuel Pressure Sensor in the engine harness is open or the connector is disconnected.
- The Main Display Module has a problem.
- Check The Display Area And The Harness.
- Turn the "ECS" switch to the OFF/RESET position.
- Check for loose terminal connections or corroded terminal connections.
- Clean corroded terminals and tighten loose connections.
- Turn the "ECS" switch to the COOLDOWN/STOP position. The "SERV CODE" indicator should be ON for CID 0460 FMI 08.
- Measure The Voltage Of The Supply Wire For The Fuel Pressure Sensor.
- Turn the "ECS" switch to the COOLDOWN/STOP position.
- Use the 7X-1710 Multimeter Probe to measure the voltage from ground wire of the Oil Pressure Sensor (Pin B) to the supply wire (Pin A).
Expected Result: The voltage should be 8.0 ± 0.5 DCV.
Results:
- OK: The voltage is 8.0 ± 0.5 DCV. The voltage is correct. Proceed to Step 3.
- Not OK: The voltage is less than 8.0 ± 0.5 DCV. The harness wiring has a problem. There is an open circuit, a short to ground in the supply wire of the Fuel Pressure Sensor, or a poor connection. Repair the harness or replace the harness. If the diagnostic code's cause is not found, proceed to Step 3.
- OK: The voltage is 8.0 ± 0.5 DCV. The voltage is correct. Proceed to Step 3.
- Measure The Signal Voltage Of The Fuel Pressure Sensor.
- Turn the "ECS" switch to the COOLDOWN/STOP position.
- Use the 7X-1710 Multimeter Probe to measure voltage from the ground wire of the Fuel Pressure Sensor (Pin B) to the supply wire (Pin C).
Expected Result: The voltage should be between 1.0 DCV and 7.0 DCV.
Results:
- OK: The voltage is between 1.0 DCV and 7.0 DCV. The signal voltage at the sensor is correct. Proceed to Step 4.
- Not OK: The voltage is NOT between 1.0 DCV and 7.0 DCV. The signal voltage at the sensor is not correct. If the voltage is greater than 7.0 DCV, proceed to Step 5. If the voltage is less than 1.0 DCV, proceed to Step 6.
- OK: The voltage is between 1.0 DCV and 7.0 DCV. The signal voltage at the sensor is correct. Proceed to Step 4.
- Measure The Fuel Pressure Signal Voltage.
- Turn the "ECS" switch to the COOLDOWN/STOP position.
- Measure the voltage between the ground wire of the Main Display Module and the signal wire contact. In order to make this measurement, use the 7X-1710 Multimeter Probe .
Expected Result: This voltage should be equal to the voltage in Step 3.
Results:
- OK: The voltage is equal to the voltage that was recorded in Step 3. The Main Display Module is receiving a valid signal voltage. The Main Display Module has a problem. Replace the Main Display Module. For more information, see Testing And Adjusting, "Module - Replace".
- Not OK: The voltage is not equal to the voltage that was recorded in Step 3. The engine harness has an open circuit in the signal circuits or the ground circuits. Repair the engine harness or replace the engine harness.
- OK: The voltage is equal to the voltage that was recorded in Step 3. The Main Display Module is receiving a valid signal voltage. The Main Display Module has a problem. Replace the Main Display Module. For more information, see Testing And Adjusting, "Module - Replace".
- Check For A Short To +Battery.
- Turn the "ECS" switch to the OFF/RESET position.
- Disconnect the Main Display Module connector and the Fuel Pressure Sensor connector.
- Use the 7X-1710 Multimeter Probe to measure the resistance that is between +Battery and the signal wire (Pin C) for the Fuel Pressure Sensor.
Expected Result: The resistance should be greater than 5000 ohms.
Results:
- OK: The resistance is greater than 5000 ohms. The harness signal wire is correct. Replace the Main Display Module. For more information, see Testing And Adjusting, "Module - Replace".
- Not OK: The resistance is less than 5000 ohms. Repair the harness or replace the harness.
- OK: The resistance is greater than 5000 ohms. The harness signal wire is correct. Replace the Main Display Module. For more information, see Testing And Adjusting, "Module - Replace".
- Check For A Short To Ground.
- Turn the "ECS" switch to the OFF/RESET position.
- Disconnect the connector for the Main Display Module and the connector for the Fuel Pressure Sensor.
- Use the 7X-1710 Multimeter Probe to measure the resistance between ground and the signal wire (Pin C) for the Fuel Pressure Sensor.
Expected Result: The resistance should be greater than 5000 ohms.
Results:
- OK: The resistance is greater than 5000 ohms. The harness signal wire is correct. Replace the Main Display Module. For more information, see Testing And Adjusting, "Module - Replace".
- Not OK: The resistance is less than 5000 ohms. Repair the harness or replace the harness.
- OK: The resistance is greater than 5000 ohms. The harness signal wire is correct. Replace the Main Display Module. For more information, see Testing And Adjusting, "Module - Replace".