MANIFOLD 4937195 - Caterpillar

Illustration 1 g00719013
Schematic for Pressure Sensor (Variable Displacement Pump Oil)This diagnostic code is recorded when the ECM determines that there are no edges on the PWM signal that is coming from the pressure sensor.The possible causes for this diagnostic code are listed:
Signal wire is shorted to ground.
Signal wire is shorted to the +battery circuit.System Response:The machine response is listed:
The stall speed for the Dig Trigger may not be correct.Note: Ensure that the diagnostic code is active and that the diagnostic code indicator is active.Test Step 1. CHECK THE PWM SIGNAL.
Connect the multimeter to the signal line that is coming from the pressure sensor.
Set the multimeter to the frequency reading.
Operate the machine.Expected Result:The frequency reading is greater than 0 Hz.Results:
YES - The frequency reading is greater than 0 Hz.Repair: The frequency is correct. Stop.
NO - The frequency reading is 0 Hz. Proceed to test step 2.Test Step 2. CHECK FOR SHORTS TO GROUND.
Turn the disconnect switch to the OFF position.
Disconnect the harness from the implement ECM.
At the harness connector for the ECM, measure the resistance between frame ground and connector contacts C (wire C460-BU) and A (wire 146-GY). Expected Result:The resistance is greater than 5000 ohms.Results:
YES - The resistance is greater than 5000 ohms. Proceed to test step 3.
NO - The resistance is less than 5000 ohms.Repair: The harness has failed. There is a short in the harness. Repair the harness or replace the harness. Stop.Test Step 3. CHECK FOR A SHORT TO THE +BATTERY CIRCUIT.
The disconnect switch remains in the OFF position.
The harness remains disconnected from the ECM.
At the harness connector for the ECM, measure the resistance between signal contact C (wire C460-BU) and contact A (wire 146-GY).Expected Result:The resistance is greater than 5000 ohms.Results:
YES - The resistance is greater than 5000 ohms.Repair: The harness circuit resistance is correct. Stop.
NO - The resistance is less than 5000 ohms.Repair: The harness has failed. There is a short between the +battery circuit and the signal wire C460-BU. Repair the harness or replace the harness. Stop.