
108 RENR9348-01
Troubleshooting Section
g01207229
Illustration 29
Terminals at the s ervice tool connector that are as sociated with
the Cat Data Link
(D) C at Data Link +
(E) Cat Data Link −
C. Perform a 45 N (10 lb) pull test on each of the
wires that are associated with the Cat Data Link.
D. Check the allen head screw on each ECM
connector for the proper torque. Also, check
the allen head screw on the engine interface
connector for the proper torque. Refer to
Troubleshooting, “Electrical Connectors - Inspect”
for the correct torque values.
Expected Result:
All connectors, pins, and sockets are completely
inserted and coupled. The harness and wiring are
free of corrosion, of abrasion, and of pinch points.
Results:
•
OK – The harness and the connectors appear to
be OK. Proceed to Test Step 2.
•
Not OK – The connectors and/or the wiring are
not OK.
Repair: Repair the connectors and/or the wiring.
Replace parts, if necessary. Ensure that all of the
seals are properly in place and ensure that the
connectors are completely coupled. Verify that the
original problem is resolved.
STOP.
Test Step 2. Check the Data Link for a
Short Circuit
A. Disconnect the J1 connector.
B. Disconnect Cat ET from the service tool connector.
C. Measure the resistance between the points that
arelistedinTa
ble 19. Be sure to wiggle the wires
in the harnesses as you make each resistance
measurement.
Table 19
Resistance Measurements for the Cat Data Link
Connector and
Terminal
Terminal
All of the other terminals on
the P1 connector
P1-8 (Cat Data Link +)
Ground stud
All of the other terminals on
the P1 connector
P1-9 (Cat Data Link -)
Ground stud
Expected Result:
Each check of the resistance indicates an open
circuit.
Results:
•
OK – Each check of the resistance indicates an
open circuit. The data link is not shorted to another
wire in the harness. Proceed to Test Step 3.
•
Not OK – At least one check of the resistance
does not indicate an open circuit.
Repair: There is a short circuit in the harness or
in a connector. Repair the connectors and/or the
wiring. Replace parts, if necessary.
STOP.
Test Step 3. Check for an Open Circuit
A. Fabricate a jumper wire that is long enough to
short circuit two terminals at the service tool
connector. Crimp connector sockets to each end
of the jumper wire.
B. Install the jumper wire between terminals D (Cat
Data Link +) and E (Cat Data Link −)attheservice
tool connector.
C. At the J1 ECM connector, measure the resistance
between P1-8 (Cat Data Link +) and P1-9 (Cat
Data Link −).
Expected Result:
The resistance check indicates that continuity exists
for the circuit.