5130, 5130B and 5230 Excavators, 784B, 785B, 785C, 789B, 789C, 793B and 793C Off-Highway Truck/Tractors and 992G, 994 and 994D Wheel Loaders Vital Information Management System (VIMS) Caterpillar

Illustration 1	g00503599
Schematic of the Torque Converter Output Speed Sensor

This fault is recorded when the VIMS module reads the engine speed signal and the signal is erratic, intermittent or incorrect.

The possible causes of this fault are listed here:

• Poor electrical connection of the machine harness connector

• The sensor is loose or the sensor is not adjusted correctly.

• The signal circuit in the machine harness is shorted to ground.

• The signal circuit is shorted to + battery in the machine harness.

• The signal circuit is open in the machine harness.

• The VIMS module has failed. This is unlikely.

1. INSPECT THE HARNESS AND THE SENSOR.

   1. Turn the disconnect switch to the OFF position.

   2. Inspect the torque converter output speed sensor and inspect the machine harness connectors of the torque converter output speed sensor.

   3. Check the torque converter output speed sensor. The sensor should be clean and tight. The harness connections are clean and tight.

      Expected Result: The torque converter output speed sensor and related wiring are correct.

      Results:

      • OK - The sensor and the machine harness are correct. Proceed to 2.

      • NOT OK - The sensor has failed or the machine harness has failed. Repair the failed component. Reference the Testing and Adjusting, "Speed Sensor - Adjust" section. STOP.

2. CHECK FOR SHORT TO GROUND IN THE SIGNAL CIRCUIT

   1. The disconnect switch remains in the OFF position.

   2. Disconnect the machine harness from the torque converter output speed sensor.

   3. Disconnect the machine harness from the VIMS module.

   4. At the machine harness connector of the VIMS module, measure the resistance between frame ground and contact 13 of the torque converter output circuit (wire 452-BU(Blue)).

      Expected Result: The resistance is greater than 5000 ohms.

      Results:

      • OK - The resistance is greater than 5000 ohms. The harness circuit is correct. Proceed to 3.

      • NOT OK - The resistance is less than 5000 ohms. The machine harness has failed. There is a short between frame ground and the torque converter output speed circuit in the machine harness. STOP.

3. CHECK FOR A SHORT TO THE + BATTERY CIRCUIT IN THE MACHINE HARNESS.

   1. The disconnect switch remains in the OFF position.

   2. The sensor remains disconnected and the VIMS module remains disconnected.

   3. At the machine harness connector for the VIMS module, measure the resistance between the + battery contact 1 (wire 113-OR(Orange)) and contact 29 of the torque converter output speed signal circuit (wire 452-BU(Blue)).

      Expected Result:The resistance is greater than 5000 ohms.

      Results:

      • OK - Resistance is greater than 5000 ohms. The harness circuit is correct. Proceed to Step 4.

      • NOT OK - Resistance is less than 5000 ohms. The machine harness is faulty. There is a short between the engine speed signal circuit and +battery. Repair the machine harness or replace the machine harness. STOP.

4. CHECK FOR OPEN SIGNAL CIRCUIT

   1. The disconnect switch remains in the OFF position.

   2. The sensor remains disconnected and the VIMS module remains disconnected.

   3. Measure the resistance between contact C of the machine harness connector of the torque converter output speed sensor (wire452-BU(Blue)) and contact 13 of the VIMS interface module machine harness connector (wire 452-BU(Blue)).

      Expected Result:The resistance is less than 5 ohms.

      Results:

      • OK - Resistance is less than 5 ohms. The signal circuit in the machine harness is correct. The VIMS module has failed. Replace the interface module. Reference the Testing and Adjusting, "Module - Replace" section. STOP.

      • NOT OK - Resistance is greater than 5 ohms. The machine harness has failed. The engine speed signal circuit is open in the machine harness. Repair the machine harness or replace the machine harness. STOP.