COOLER AS-ENGINE OIL 2831293 - Caterpillar

Possible conditions that can cause this diagnostic code are listed:
One or both of the switch inputs is shorted to a ground source.
The switch has failed.
The ECM has failed. A failure of the Transmission/Chassis ECM 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, that all connections are secure and that all connections are 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. Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected. Test Step 1. VALIDATE THE SWITCHThe following procedure will use Cat ET to check the status of the switch.
Locate a laptop that is loaded with a current version of Cat ET.
Use the proper cable to connect the laptop to the Cat ET connector on the machine.
Turn the key start switch and the disconnect switch to the ON position.
Turn the switch ON and OFF. Compare the condition of the circuit displayed on the Cat ET screen to the table below
Table 2
Switch Not Depressed Switch Depressed Likely Problem
OFF ON Switch Intermittent or Normal
Voltage Below Normal ON N/O Wire Shorted to Ground
OFF Voltage Below Normal N/C Wire Shorted to Ground
Voltage Below Normal Voltage Below Normal Switch has Failed Expected Result:The condition of the switch is intermittent or normal.Results:
OK - The condition of the switch is intermittent or normal.Repair: Check the circuit. Use the Cat Electronic Technician (ET) service tool, if available, in order to perform a wiggle test on the machine wiring harness. The wiggle test can detect momentary or intermittent shorts or opens in the machine wiring harness.STOP
NOT OK - Repair: If the problem is a short to ground of the normally open wire (wire F781-BR(Brown)), check for a short to ground in wire F781-BR(Brown). Refer to “CHECK THE SWITCH CIRCUITS FOR AN OPEN”.If the problem is a short to battery of the normally closed wire (wire F784-YL(Yellow)), check for a short to ground in wire F784-YL(Yellow). Refer to “CHECK THE SIGNAL CRICUIT FOR A SHORT TO GROUND”.If both wires are shorted to ground or the switch is suspected of failing, refer to “CHECK THE SIGNAL CIRCUIT FOR A SHORT TO GROUND”.STOPTest Step 2. CHECK THE SWITCH
Turn the 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 while disconnecting the "Left Joystick" J2 connector from the machine harness. Expected Result:If CID 0622 FMI 03 becomes active, the machine harness and the ECM are most likely OK.If no CID 622 codes are active, the harness is most likely grounded in one circuit.If CID 0622 FMI 04 remains active, both circuits likely have a short to ground.Results:
OK - The CID 0621