FAN GP-BLOWER 1635811 - Caterpillar

Illustration 1 g02042576
Schematic of the "Auxiliary Pedal 2 Control Pressure" SensorThis diagnostic code is associated with the "Auxiliary Pedal 2 Control 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 (VDC) between the signal contact 3 (wire N794-GY) and the ground contact 2 (wire 235-BK).Expected Result:The voltage is 8.0 0.5 VDC. Results:
OK - The voltage is 8.0 0.5 VDC. 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 VDC.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) 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 position.
Measure the resistance between the signal contact 3 (wire N794-GY) and contact 1 (wire J850-WH) of the machine harness connector for the sensor. Expected Result:The resistance is greater than 5000 ohms.Results:
OK - The resistance is greater than 5000 ohms. The harness circuit resistance is correct. Proceed to Test Step 4.
NOT OK - The resistance is less than 5000 ohms.Repair: The machine harness has failed. There is a short between the +battery circuit and the signal circuit in the machine harness. Repair the machine harness or replace the machine harness.STOPTest Step 4. CHECK FOR AN OPEN 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 position.
Measure the resistance of the signal circuit from the connector contact J1-38 (wire N794-GY) of the Machine ECM