PIN-DOWEL 1146306 - Caterpillar

System Operation Description:The green LED of the status indicator informs the operator that the machine security system (MSS) ECM has recognized a valid key. The problem may be unrelated to the MSS. The source of the problem that is preventing an engine start can come from several sources. Ensure that all of the standard requirements for starting the machine have been met. A few examples of the requirements are listed here:
Interlocks in the operator seat
Hydraulic interlocks
Gear of the machine
Fuel levelThis troubleshooting procedure will eliminate the MSS as a source of the starting problem.Note: The wires that are identified in this procedure are not present on every machine. If the wire that is identified in this procedure is not present, proceed to the next Test Step.Test Step 1. CHECK THE CAT DATA-LINK.
Connect the Caterpillar Electronic Technician (Cat ET) service tool to the machine.
Use a valid key to turn the keyswitch to the ON position.
Use the Cat ET service tool to determine the status of the Cat data-link. Expected Result:The Cat data-link is communicating with all the ECMs that are installed on the machine.Note: Some machines are equipped with only the MSS ECM.Results:
YES - The Cat data-link is communicating with all the ECMs that are installed on the machine. Proceed to Test Step 2.
NO - The Cat data-link is not communicating with all the ECMs that are installed on the machine. The Cat data-link has failed.Repair: Repair the Cat data-link circuits in the harness.STOPTest Step 2. CHECK THE SYSTEM VOLTAGE AT THE MSS ECM.
Measure the voltage between pin 1 and pin 3 of the MSS ECM.Expected Result:The voltage is approximately system voltage.Results:
YES - The voltage is approximately system voltage. Proceed to Test Step 3.
NO - The voltage is not approximately system voltage.Repair: Check the battery and the associated wiring in the machine harness. STOPTest Step 3. CHECK THE VOLTAGE FROM THE KEY SWITCH TO THE DRIVER (INPUT No. 1) OF THE ECM.
Turn the keyswitch to the ON position.
Measure the voltage between pin 9 and pin 3 if the wires are present. Record the reading.
Measure the voltage between pin 24 and pin 3 and record the reading.
Measure the voltage between pin 64 and pin 3 if the wires are present. Record the reading. Expected Result:Voltage should be present for all of the measurements. The voltage