Generator Set Control Panel for Switchgear Conversion Caterpillar

Illustration 1	g00565311
Schematic For The Temperature Sensor (Right Side)

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 when an engine is serviced. This schematic should also be used to find the Main Display Module's connector contact that corresponds to the current CID that is shown.

When the Main Display Module reads an abnormal sensor signal, the diagnostic code is recorded. The Main Display Module's input circuitry cannot recognize the sensor signal. As a result of this diagnostic condition, the corresponding Alert indicator is flashing and the Gauge Needle is in the warning region. The following examples are possible causes.

• The RH Exhaust Temperature Sensor has a problem.

• The ground circuit of the RH Exhaust Temperature Sensor that is located in the engine harness is open.

• The signal circuit of the RH Exhaust Temperature Sensor is shorted to +Battery. This circuit is located in the engine harness.

• The signal circuit of the RH Exhaust Temperature Sensor 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.

   3. Clean corroded terminals and tighten loose connections.

   4. Turn the "ECS" switch to the COOLDOWN/STOP position. The "SERV CODE" indicator should be ON for CID 0828 FMI 08.

2. Measure The Voltage Of The Supply Wire For The RH Exhaust Temperature Sensor.

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

   2. 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 RH Exhaust Temperature Sensor, or a poor connection. Repair the harness or replace the harness. If the cause of the diagnostic is not found, proceed to Step 3.

3. Measure The Signal Voltage Of The RH Exhaust Temperature Sensor.

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

   2. Use the 7X-1710 Multimeter Probe to measure voltage from the ground wire of the RH Exhaust Temperature 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.

4. Measure The Signal Voltage Of The RH Exhaust 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 of the Main Display Module to the signal wire contact.

      Expected Result: The 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 does not equal 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.

5. Check For A Short To +Battery.

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

   2. Disconnect the Main Display Module connector and the RH Exhaust Temperature Sensor connector.

   3. Use the 7X-1710 Multimeter Probe to measure the resistance that is between +Battery and the RH Exhaust Temperature Sensor's signal wire (Pin C).

      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.

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 RH Exhaust Temperature Sensor.

   3. Use the 7X-1710 Multimeter Probe to measure the resistance between ground and the signal wire (Pin C) for the RH Exhaust Temperature 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.