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

This diagnostic code is recorded when the ECM reads the voltage of the 8 DCV sensor supply circuit and the voltage is below normal.

1. CHECK THE VOLTAGE AT THE INTERFACE MODULE.

   1. Turn the disconnect switch and the key start switch to the ON position.

   2. Check the voltage at the connector of the interface module from contact 26 (sensor supply) to contact 2 (ground). Use the 7X-1710 Cable probes to measure the voltage. Do NOT disconnect the machine harness from the VIMS main module.

      Expected Results: Voltage is 8.0 ± 0.5 DCV.

      Results:

      • OK - Voltage is 8.0 ± 0.5 DCV. The sensor supply voltage is correct. Check the message center in order to verify that the same diagnostic code is present. If the diagnostic code is still present the interface module has failed. Replace the module. Refer to the Testing and Adjusting, "Module - Replace" section. STOP.

      • NOT OK - Voltage is NOT 8.0 ± 0.5 DCV. The voltage is less than 8.0 ± 0.5 DCV. The sensor supply voltage is NOT correct. proceed to 2.

2. CHECK FOR SHORT TO GROUND

   1. Turn the key start switch and the disconnect switch to the OFF position.

   2. Disconnect the machine harness from the VIMS interface module.

   3. At the VIMS interface module harness connector, measure the resistance between frame ground and the contact 26 of the sensor supply circuit.

      Expected Results: Resistance is greater than 5000 ohms.

      Results:

      • OK - Resistance is greater than 5000 ohms. The harness circuit resistance is correct. The VIMS interface module has failed. Replace the VIMS interface module. Refer to the Testing and Adjusting, "Module - Replace" section. STOP.

      • NOT OK - Resistance is less than 5000 ohms. The machine harness or a sensor has failed. Proceed to 3.

3. DISCONNECT THE SENSORS.

   1. The key start switch and the disconnect switch remain in the OFF position.

   2. One at a time disconnect any sensor that uses the +8 DCV interface module sensor supply from the machine harness, that is associated with this diagnostic code.

   3. After disconnecting the sensor (s), check the resistance from frame ground to contact 26 (sensor supply) of the machine harness connector for the VIMS interface module.

      Expected Results: Resistance is greater than 5000 ohms.

      Results:

      • OK - Resistance is greater than 5000 ohms. The harness circuit resistance is correct. The sensor that was just disconnected has failed. Replace the sensor. STOP.

      • NOT OK - Resistance is less than 5000 ohms. If the resistance is less than 5000 ohms after all the sensors have been disconnected from the machine harness. The machine harness is shorted to ground. Repair the machine harness or replace the machine harness. STOP.