
106 RENR9348-01
Troubleshooting Section
Test Step 5. Check for an Open Circuit
A. Verify that all of the connections are disconnected.
B. Fabricate a jum
per wire. Use the jumper wire in
order to create a short circuit between terminals G
and F on the service tool connector.
C. Measure the resistance between terminals P1-50
(CAN data link +) and P1-34 (CAN data link -).
D. Removethejumperwirefromtheservicetool
connector.
Expected Result:
The resistanc
e is less than ten Ohms.
Results:
•
OK – The resistance is less than ten Ohms. There
is not an open circuit. Proceed to Test Step 6.
•
Not OK – The resistance is more than ten Ohms.
There is an open circuit or excessive resistance in
the circuit.
Theremaybeaprobleminaconnector.
Repair: Repair the wiring and/or the connector.
Replace part
, if necessary. Verify that the problem
is resolved.
STOP.
Test Step 6. Check the J1939 Display
A. Connect the J1939 display to another engine.
B. Operate the
engine and monitor the J1939 display.
Expected Result:
The J1939 display operates properly.
Results:
•
OK – The J1939 display operates properly on
another eng
ine.
Repair: Connect the display to the original engine.
If the displ
ay operates correctly, there may be
a problem with an electrical connector. Refer to
Troubleshooting, “Electrical Connectors - Inspect”.
If the display does not operate correctly on the
original engine, there may be a problem with the
ECM.
It is unlikely that the ECM has failed. Perform
this entire pro
cedure again. Replace the ECM if
the display does not operate correctly. Refer to
Troubleshooting, “Replacing the ECM”.
STOP.
•
Not OK – The J19
39 display does not operate
properly on another engine.
Repair: Repla
ce the J1939 display. Verify that the
problem is resolved.
STOP.
i02415043
Cat Data Link
Circuit - Test
SMCS Code: 1901-038
System Operation Description:
Note: This pr
ocedure checks for an open circuit
or for a short circuit in the Cat Data Link. If you
are experiencing problems with communications
between the C
aterpillar Electronic Technician (ET)
and the Electronic Control Module (ECM), refer
to Troubleshooting, “Electronic Service Tool Will
Not Communi
cate with ECM” before you use this
procedure.
The Cat Data
Link is the standard data link that
is used by the ECM to communicate with C at ET.
The ECM communicates with Cat ET in order to
share stat
us information and diagnostic information.
Cat ET can also be used to configure the ECM
parameters. This information will not be available if
communica
tion fails between the ECM and Cat ET.
g01207158
Illustration 24
Schematic for the C at Data Link
Test Step 1. Inspect the Electrical
Connectors and the Wiring
A. Remove the electrical power from the ECM.