SUPPORT 4P2837 - Caterpillar

Illustration 1 g06069736
The pump pressure sensors are located in the rear center of the main control valve.
(1) Pump 1 pressure sensor
(2) Pump 2 pressure sensor
Illustration 2 g02038058
Schematic of the "Hydraulic Pump 2 Outlet Pressure" Sensor
This diagnostic code is associated with the "Hydraulic Pump 2 Outlet Pressure" Sensor. This diagnostic code is recorded when the Machine ECM reads the sensor signal voltage and the voltage is too high.The possible causes of this diagnostic code are listed below:
The sensor has failed.
The sensor supply or the ground circuit in the machine harness is open.
The signal circuit in the machine harness is shorted to the +battery.
The signal circuit in the machine harness is open or the sensor is disconnected.
The Machine ECM has failed. A failure of the ECM is unlikely.Test Step 1. CHECK THE CONTROL AND THE HARNESS.
Turn the disconnect switch and the key start switch to the ON position.
Disconnect the machine harness from the pump pressure sensor.
At the machine harness connector for the sensor, measure the voltage (DCV) between the signal contact 3 (wire T967-YL(Yellow)) and the ground contact 2 (wire 235-BK(Black)).Expected Result:The voltage is 8.0 0.5 DCV.Results:
OK - The voltage is 8.0 0.5 DCV.Repair: The Machine ECM and the harness are correct. The sensor has failed. Replace the sensor.STOP
NOT OK - The voltage is NOT 8.0 0.5 DCV.Repair: The Machine ECM or the harness has failed.Proceed to Test Step 2.Test Step 2. CHECK THE GROUND CIRCUIT OF THE HARNESS
The sensor remains disconnected from the machine harness.
Turn the disconnect switch and the key start switch to the OFF position.
Disconnect the J1 and J2 machine harness connectors from the Machine ECM.
At the machine harness connector for the sensor, measure the resistance between ground contact 2 (wire 235-BK(Black)) and frame ground. Expected Result:The resistance is less than 5.0 ohms.Results:
OK - The resistance is less than 5.0 ohms. The harness resistance is correct. Proceed to Test Step 3.
NOT OK - The resistance is greater than 5.0 ohms.Repair: The ground circuit in the harness has failed. There is an open circuit between the ground contact and frame ground. Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK FOR A SHORTED HARNESS
The sensor and the Machine ECM remain disconnected from the machine harness.
The disconnect switch and the key start switch remain in the OFF