ELBOW AS 3498519 - Caterpillar

Illustration 1 g01157541
Schematic of the hoist control position sensorThis diagnostic code is associated with the hoist control position sensor. This diagnostic code is recorded when the Power Train/Chassis Electronic Control Module (ECM) reads the signal voltage of the sensor as being too low. The possible causes of this diagnostic code are listed:
Wire M997-PU is shorted to ground.
The sensor has failed.
The ECM may have failed. The ECM failing would be unlikely.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 0773 FMI 04 is active before performing this procedure.Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.System Response:The status of the hoist control position sensor is unknown. The hoist system is unable to raise the dump body. Also, the hoist system is unable to lower the dump body. The gear of the machine is limited. The gear is limited to the current setting for the gear limit function. The hoist system will remain in the hold position until the hoist control lever is returned to the HOLD position. The hoist system will operate correctly after the diagnostic code has been corrected.Test Step 1. CHECK THE SENSOR
Turn the battery disconnect switch and the key start switch to the ON position.
Ensure that the diagnostic code is active.
Observe the status of the diagnostic code. Disconnect the machine harness from the sensor.Expected Result:The diagnostic code will remain active if the sensor is not the cause of the diagnostic code. The sensor is the cause of the diagnostic code if the diagnostic code is no longer active.Results:
YES - The diagnostic code remains active. The sensor is not faulty. The machine harness may be faulty or the ECM may be faulty. Proceed to Test Step 2.
NO - The diagnostic code is no longer active.Repair: The machine harness and the ECM are operating properly. The sensor is faulty. Replace the sensor.STOPTest Step 2. CHECK THE SIGNAL CIRCUIT FOR A SHORT TO GROUND
The sensor remains disconnected from the machine harness.
Turn the key start switch and the battery disconnect switch to the OFF position.
Disconnect the machine harness connector J1 and J2 from the ECM.
At the J1 and J2 machine harness connectors, measure the resistance from contact J2-15 (M997-PU) to all source of frame ground.Expected Result: The resistance should be greater than 5 ohms. Results:
YES - The resistance is greater than 5 ohms. The machine harness is correct. Proceed to Test Step 3.
NO - The resistance is less than 5 ohms.Repair: There is a short in the machine harness. The short is between the signal circuit (wire M997-PU) and the circuit with the low resistance measurement. Repair the machine harness or replace the machine harness. STOPTest Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS
Inspect the contacts of the harness connectors and clean the harness connectors.
Reconnect all the harness connectors.
Turn the battery disconnect switch and the key start switch to the ON