BODY AS-ACTUATOR 9W0326 - 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 R785-PU). This diagnostic code is active when the ECM detects a voltage on the signal wire that is greater than 4.8 volts.Possible causes of the diagnostic code are listed:
The return circuit is open.
The signal circuit is shorted to +battery.
The signal circuit is open or the sensor is disconnected.
The sensor has failed.
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.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 FOR AN OPEN IN THE SIGNAL CIRCUIT.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the J1 machine harness connector from the ECM.
At the machine harness connector for the sensor, install a jumper wire from contact 3 (wire R785-PU) to contact 2 (wire J764-BR).
At the machine harness connector J1, measure the resistance from contact J1-56 (wire J764-BR) to contact J1-37 (wire R785-PU).Expected Result:The resistance should measure less than 5 ohms.Results:
OK - The resistance measures less than 5 ohms. Proceed to 2.
NOT OK - The resistance measurement is greater than 5000 ohms.Repair: There is an open in either the signal circuit or there is an open in the return circuit. Repair the harness or replace the harness.STOPTest Step 2. CHECK THE SIGNAL CIRCUIT FOR A SHORT.
The disconnect switch and the key start switch remain in the OFF position.
The machine harness connector J1 remains disconnected.
Remove the jumper wire from contact 3 (wire R785-PU) to contact 2 (wire J764-BR).
Disconnect the machine harness connector J1 from the ECM.
At the J1 machine harness connectors for the ECM, measure the resistance for the signal contact of the sensor J1-37 (wire R785-PU) to all other J1 contacts.Expected Result:Each resistance measurement should be greater than 5000 ohms.Results:
OK - Each resistance measurement is greater than 5000 ohms. Repair: The sensor has failed. Replace the sensor and verify that the new sensor corrected the problem. 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 - One or more resistance measurement is less than 5 ohms.Repair: There is a short in the machine harness. The short is between the signal circuit and the circuit with the low resistance measurement. Repair the harness or replace the harness.STOP