3508, 3508B, 3508C, 3512, 3512B, 3512C, 3516, 3516B and 3516C Engines Caterpillar Monitoring System Caterpillar

Note: Ensure that the diagnostic code (CID FMI) is on hold. Ensure that the "SERV CODE" indicator is ON. Use the electrical system schematic of the engine that is being serviced to find the connector contact that is located on the Main Display Module. The connector contact should correspond to the current CID that is shown on the Display Area.

The diagnostic code is recorded when the Main Display Module reads an abnormal sensor signal. The abnormal signal means that the signal is not identifiable by the internal circuitry of the Main Display Module. The corresponding Indicator Lamp begins flashing as a result of this diagnostic condition. Also, the Gauge Needle is in the warning region. The following examples are possible causes.

• The engine oil temperature sensor has a problem.

• The ground circuit for the engine oil temperature sensor that is located in the engine harness is open.

• The signal circuit for the engine oil temperature sensor that is located in the engine harness is shorted to +battery.

• The signal circuit for the engine oil temperature sensor that is located in the engine harness is open or the connector is disconnected.

• The Main Display Module has a problem.

1. Check the Display Area and the Harness.

   1. Turn the "ECS" switch to the OFF/RESET position.

   2. Check for loose terminal connections or corroded terminal connections to the engine oil pressure sensor.

   3. Clean corroded terminals and tighten loose connections.

   4. Turn the "ECS" switch to the COOLDOWN/STOP position.

   5. The "SERV CODE" indicator should be ON for the diagnostic code CID 0175 FMI 08.

2. Measure the Voltage of the Supply Wire for the Engine Oil Temperature Sensor.

   1. Turn the "ECS" switch to the COOLDOWN/STOP position.

   2. Use the 7X-1710 Multimeter Probe to measure the voltage from the ground wire for the Engine Oil Temperature 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. Proceed to Step 3.

      • Not OK - The voltage is less than 0.5 DCV. The harness wiring has a problem. There is an open circuit, a short to ground in the supply wire for the Engine Oil Temperature Sensor or a poor connection. Repair the harness or replace the harness. If the cause of the diagnostic fault is not found, proceed to Step 3.

3. Measure The Engine Oil Temperature Sensor Voltage.
   • If the voltage is between approximately 1.0 DCV and 7.0 DCV, the signal voltage at the sensor is correct. Proceed to Step 4.

   • If the voltage is not between approximately 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.

   1. Turn the "ECS" switch to the COOLDOWN/STOP position.

   2. Use the 7X-1710 Multimeter Probe to measure the voltage from the ground wire for the Engine Oil Temperature Sensor (pin B) to the supply wire (pin C).

      Expected Result: The voltage should be approximately between 1.0 DCV and 7.0 DCV.

      Results:

      • OK - The voltage is between approximately 1.0 DCV and 7.0 DCV. The signal voltage at the sensor is correct. Proceed to Step 4.

      • Not OK - The voltage is greater than 7.0 DCV. The signal voltage at the sensor is not correct. Proceed to Step 5.

      • Not OK - The voltage is less than 1.0 DCV. The signal voltage at the sensor is not correct. Proceed to Step 6.

4. Measure The Signal Voltage Of The Engine Oil Temperature Sensor.

   1. Turn the "ECS" switch to the COOLDOWN/STOP position.

   2. Use the 7X-1710 Multimeter Probe to measure the voltage from the connector contact of the ground wire on the Main Display Module to the signal wire connector contact.

      Expected Result: The voltage should be similar to the voltage that was measured in Step 3.

      Results:

      • OK - The voltage is similar to the voltage that was measured 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. See Testing And Adjusting, "Module - Replace" for more information.

      • Not OK - The value is not similar to the voltage that was measured in Step 3. The engine harness has an open circuit in the signal circuits or the engine harness has an open circuit in the ground circuits. Repair the engine harness or replace the engine harness.

5. Check For A Short To +Battery.

   1. Turn the "ECS" switch to the OFF/RESET position.

   2. Disconnect the connector of the Main Display Module.

   3. Use the 7X-1710 Multimeter Probe to measure the resistance that is between +battery and the signal wire (pin C) for the Engine Oil Temperature Sensor.

      Expected Result: The resistance should be greater than 5000 ohms.

      Results:

      • OK - The resistance is greater than 5000 ohms. The signal wire for the harness is correct. Replace the Main Display Module. See Testing And Adjusting, "Module - Replace" for more information.

      • Not OK - The resistance is less than 5000 ohms. Repair the harness or replace the harness.

6. Check For A Short To Ground.

   1. Turn the "ECS" switch to the OFF/RESET position.

   2. Disconnect the connector for the Main Display Module and the connector for the Engine Oil Temperature Sensor.

   3. Use the 7X-1710 Multimeter Probe to measure the resistance that is between the ground wire and the signal wire (pin C) of the Engine Oil Temperature Sensor.

      Expected Result: The resistance should be greater than 5000 ohms.

      Results:

      • OK - The resistance is greater than 5000 ohms. The resistance of the signal wire for the harness is correct. Replace the Main Display Module. See Testing And Adjusting, "Module - Replace" for more information.

      • Not OK - The resistance is less than 5000 ohms. Repair the harness or replace the harness.