PLATE-COVER 9W0338 - Caterpillar

Illustration 1 g01323956
Schematic of the Travel Pressure SensorThis diagnostic code is associated with the Travel Pressure Sensor. This is an analog sensor which produces a voltage to the ECM on pin J1-37 (wire J785-PU). This diagnostic code is active when the machine ECM detects a voltage on the signal wire that is less than 0.2 volts. The possible causes of this failure are listed here:
The sensor has failed.
There is an open in the supply wire.
The signal circuit in the machine harness is shorted to ground.
The machine ECM has failed. 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.System Response:A level 1 warning will be generated. The ECM will set the drive loop pressure reading to 0 kPa (0 psi).Test Step 1. CHECK THE VOLTAGE AT THE SENSOR.
Turn the disconnect switch and the key start switch to the ON position.
Disconnect the sensor from the machine harness.
At the machine harness connector for the sensor, measure the voltage between supply contact 1 (wire J844-GY) and return contact 2 (wire J764-BRExpected Result:The voltage is 5 0.3 DCV.Results:
OK - The voltage is 5 0.3 DCV. Proceed to Test Step 2.
NOT OK - The voltage is NOT 5 0.3 DCV.Repair: There is an open in the machine harness. Repair the machine harness or replace the machine harness.STOPTest Step 2. CHECK THE SENSOR.
Disconnect the machine harness from the sensor. Expected Result:The diagnostic code changes from CID 0148 FMI 04 to CID 0148 FMI 03. Results:
OK - The diagnostic code changed to CID 0148 FMI 03. This indicates that the failure is no longer present. The sensor has failed.Repair: Replace the sensor.STOP
NOT OK - The diagnostic code CID 0148 FMI 04 remained active. This indicates that the failure remains present. The sensor is not causing the failure. Proceed to test step 3.Test Step 3. CHECK THE HARNESS.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the J1 machine harness connector from the ECM.
At the J1 machine harness connectors for the ECM, measure the resistance from the signal contact of the sensor J1-37 (wire R785-PU) to all other J1 contacts. Expected Result:The resistance is greater than 5000 ohms. Results:
OK - The resistance is greater than 5000 ohms. The harness circuit resistance is correct. The machine ECM may have failed. Repair: If the cause of the problem is not found, contact the Technical Communicator for your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECM requires replacement, see Troubleshooting, "Electronic Control Module (ECM) - Replace".STOP
NOT OK - The resistance is less than 5000 ohms. The machine harness has failed. There is a short between frame ground and the signal circuit in the