CLIP 0000639 - Caterpillar

Which Generate This Code:The Machine Security System (MSS) is not responding to requests from the Electronic Control Module (ECM) for the engine.
System Response:The ECM logs the diagnostic code. The diagnostic code may be viewed on a display module or on the Caterpillar Electronic Technician (ET). The ECM will not send the start signal to the start relay and injection is disabled.
The engine will not crank.Test Step 1. Ensure that the MSS is Properly Installed
Ensure that the MSS is properly installed. If MSS has been disabled or removed from the machine, you must program the "Security System Immobilizer Installation Status" to "Not Installed". Factory passwords are required.Results:Continue to the next test step.Test Step 2. Perform the following diagnostic procedure: Cat Data Link Circuit - TestResults:
OK - STOP