CARRIER-PLANETARY 1345996 - Caterpillar

Illustration 1 g01310348
Machine ECM 5 VDC Sensor Power Supply connectionsThis diagnostic code is associated with the Machine ECM 5 volt sensor power supply. The 5 volt sensor power supply provides power for the drive pressure sensor.The CID 0262 FMI 04 diagnostic code is activated when the ECM detects that the voltage of the 5 volt power supply circuit is lower than normal.The following conditions could cause this diagnostic code:
A sensor has failed.
The power supply circuit is shorted to a ground 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, secure and 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. Clear the diagnostic codes when the problem has been corrected. Verify that the CID 0262 FMI 04 is active before performing this procedure.System Response:A level 1 warning will be generated. Any sensor using this is disabled.Test Step 1. CHECK THE POWER SUPPLY AT THE ECM
Turn the disconnect switch and the key start switch to the OFF position.
At ECM connector J1, use a 151-6320 Removal Tool or a similar tool to remove the supply wire and socket at contact J1-11 (wire J844-GY) and the return wire and socket at contact J1-21 (wire J767-GY) from the connector. The machine harness connector J1 remains connected to the ECM.
Turn the disconnect switch and the key switch to the ON position.
Use the multimeter probes in order to make contact on the ECM connector pins. Measure the voltage at the ECM pins between the power supply contact J1-11 and the return contact J1-21.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 J1 connector back into the original locations. Proceed to Test Step 2.
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 your dealership's Technical Communicator for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECM requires replacement, refer to Troubleshooting, "Electronic Control Module (ECM) - Replace".STOPTest Step 2. CHECK THE SENSORS
Turn the key switch and the disconnect switch to the ON position.
Disconnect the pressure sensor from the machine harness.
After disconnecting the sensor, check the status of the CID 0262 FMI 04 diagnostic code.Expected Result:The CID 0262 FMI 04 diagnostic code is no longer active.Results:
OK - The CID 0262 FMI 04 diagnostic code is not active when the sensor is disconnected. The harness circuit is correct. The sensor that was just