User's Manual

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i06222432
Engine Does Not Crank and
Status Indicator Is Green
SMCS Code: 7631-035
The green LED of the status indicator informs the
operator that the machine security system (MSS3s)
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 level
This 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.
Table 9
Troubleshooting Test Steps Values Results
1. CHECK THE DATA LINKS.
A. Connect the Caterpillar Electronic Technician (Cat ET)
service tool to the machine.
B. Use a valid key to turn the keyswitch to the ON
position.
C. Use the Cat ET service tool to determine the status of
the Cat data-link.
The data links are
communicating
with all the ECMs
that are installed on
the machine.
Note: Some ma-
chines are
equipped with only
the MSS3s ECM.
Yes - The data links are communicating with all the ECMs that
are installed on the machine.
Proceed to Test Step 2.
No - The data links are not communicating with all the ECMs
that are installed on the machine. The Cat data-link has failed.
Repair:Repair the data link circuits in the harness.
STOP.
(continued)
UENR7061 31
Symptom Procedures