FILM-INSTRUCTION 3498603 - Caterpillar

Illustration 1 g01964827
Schematic of the 5 Volt sensor supply
Sales model 854K/992K
This diagnostic code is associated with the 5 volt sensor power supply of the VIMS ECM. The 5 volt sensor power supply provides power for the pump pressure sensor of the engine fan.The CID 0262 FMI 03 diagnostic code is activated when the ECM detects higher than normal voltage of the 5 volt power supply circuit.The following causes could signal this diagnostic code:
The power supply circuit is shorted to a higher voltage source.
The ECM has failed. This is unlikely.Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean and secure. Verify that all connections are in good condition. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the problem has been corrected. Verify that the CID 0262 FMI 03 is active before performing this procedure.System Response:A warning level 1 will be generated. Any sensor that uses this supply is disabled.Test Step 1. CHECK THE VOLTAGE AT THE SENSORS
Turn the disconnect switch and the key start switch to the ON position.
Disconnect the machine harness connector from the pressure sensor.
Measure the voltage from contact A (wire R997-OR(Orange)) to return contact B (wire J843-BK(Black)) at the machine harness connector for the pressure sensor. Expected Result:The voltage measurement is 5.0 0.4 DCV.Results:
OK - The voltage measurement is 5.0 0.4 DCV. The voltage is correct. Proceed to Test Step 4.
NOT OK - The voltage measurement is greater than 5.0 0.4 DCV. The measurement is not correct. Proceed to Test Step 2.Test Step 2. CHECK THE POWER SUPPLY AT THE ECM
Turn the disconnect switch and the key start switch to the OFF position.
Use a 151-6320 Removal Tool or a similar tool to remove the wire at contact J2-63 (wire R997-OR(Orange)) and the wire at contact J2-53 (wire J843-BK(Black)) from the connector. The machine harness connector J2 remains connected to the ECM.
Turn the disconnect switch and the key start switch to the ON position.
Use the multimeter probes in order to make contact on the pins in the ECM connector. Measure the voltage at the ECM pins between contact J2-63 and contact J2-53. Expected Result:The voltage measurement is 5.0 0.4 DCV.Results:
OK - The voltage measurement is 5.0 0.4 DCV. The voltage is correct. The ECM power supply is correct. Turn the key start switch and the disconnect switch to the OFF position. Install the wires and sockets that were removed from the J2 connector back into the original locations. Proceed to Test Step 3.
NOT OK - The voltage measurement is greater than 5.0 0.4 DCV. The ECM power supply is not correct.Repair: Prior to replacing an ECM, always contact