Troubleshooting

Table 63
Troubleshooting Test Steps
Values Results
1. Inspect Electrical Connectors and Wiring
A. Turn the keyswitch to the OFF position.
B. Inspect the connectors in the circuit for the CAN data link.
Refer to Troubleshooting, “Electrical Connectors - Inspect” for
details.
C. Perform a 30 N (6.7 lb) pull test on each of the wires that are
associated with the CAN data link.
D. Check all of the wiring associated with the CAN data link for
abrasions and pinch points.
Damaged
wire or
connector
Result: A damaged wire or damaged connector was found.
Repair the damaged wire or the damaged connector.
Use the electronic service tool to clear all logged diagnostic
codes. Verify that the repair eliminates the fault.
Result: A damaged wire or damaged connector was not
found.
Proceed to Test Step 2.
2. Check the Data Link Terminating Resistance
A. Disconnect the P1 connector from the ECM.
B. Measure the resistance between the P1:46 and P1:47.
Between 50
Ohms and 70
Ohms
Result: The resistance is less than 50 Ohms - there is a
short circuit in the harness.
Repair the connectors or the harness and/or replace the
connectors or the harness. Ensure that all of the seals are
correctly in place and ensure that the connectors are cor-
rectly connected.
Use the electronic service tool in order to clear all logged di-
agnostic codes and then verify that the repair eliminates the
fault.
Result: The resistance is between 110 and 130 Ohms - one
of the terminating resistors may have failed.
Locate the two terminating resistors and remove the two ter-
minating resistors from the harness. The terminating resis-
tors may be located in other ECMs on the data link. Refer to
the Electrical Schematic.
Measure the resistance of the two terminating resistors.
If one of the terminating resistors is incorrect, replace the
faulty terminating resistor.
If the two terminating resistors are between 50 and 70 Ohms
each, proceed to Test Step 4.
Result: The resistance is greater than 150 Ohms.
Proceed to Test Step 3.
Result: The resistance is between 50 and 70 Ohms
This is the correct resistance. The fault may be in the con-
nection to other devices on the data link.
Proceed to Test Step 3.
(continued)
126 UENR0612-07
Circuit Tests
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