GEAR-PUMP DRIVE 8N0560 - Caterpillar

System Operation Description:A solid red LED in the status indicator indicates that the MSS has not recognized a valid electronic key for that machine. This condition can be caused by several problems. One or more of the problems that are listed here could be responsible for this condition. If the electronic key has been damaged, the MSS will not disarm and the machine will not start. If a problem exists in the exciter coil, the MSS will be unable to read the electronic key. If the wiring for the exciter coil is damaged, the MSS will be unable to read the electronic key.Note: Ensure that you have only one electronic key near the exciter coil when the MSS reads the key. If there is more than one electronic key near the exciter coil, the MSS ECM will not be able to read the key and the machine will not start.Test Step 1. CHECK THE KEY.
Connect the Caterpillar Electronic Technician (ET) to the Service Connector.
Insert a valid electronic key for the machine in the key start switch.
Turn the key switch to the ON position.
Go to the "Service/Security Management" screen. Check the "Current Key Information".
Check the "ID1" and "ID2" for the key that is in the key start switch.Expected Result:The MSS reads the ID1 code and the ID2 code as 0.Results:
YES - The MSS reads the ID1 code and the ID2 code as 0. The key may have failed or the problem may exist in the exciter coil. Proceed to Test Step 2.
NO - The MSS reads the ID1 code and the ID2 code correctly. The key has been read by the MSS ECM, but the MSS is still armed. This indicates that the key in the key start switch is not authorized for that machine.Repair: Program that key into the MSS ECM or use a different key. Stop.Test Step 2. CHECK THE EXCITER COIL.
Disconnect the exciter coil from the wiring harness.
Measure the resistance on the leads of the exciter coil. Expected Result:The resistance is approximately 1 ohm.Results:
YES - The resistance is approximately 1 ohm. Proceed to Test Step 3.
NO - The resistance is greater than approximately 1 ohm. The exciter coil has failed.Repair: Replace the exciter coil. Stop.Test Step 3. CHECK THE WIRING OF THE MACHINE HARNESS FOR AN OPEN CIRCUIT.
The exciter coil remains disconnected from the wiring harness.
On the harness side of the connector for the exciter coil, install a jumper wire between pin 1 and pin 2 .
Disconnect the wiring harness connector from the MSS ECM.
Measure the resistance between pin 7 and pin 53 of the connector for the MSS ECM.Expected Result:The resistance is less than 5 ohms.Results:
YES - The resistance is less than 5 ohms between pin 7 and pin 53. The wiring for the exciter coil is correct. Proceed to Test Step 4.
NO - The resistance is greater than 5 ohms between pin 7 and pin 53. There is a problem in the wiring for the exciter coil.Repair: Check the wiring harness for signs of