KENR6933 113
Troubleshooting Section
Results:
•
OK – Proceed to Test Step 2.
•
Not OK
Repair: Perform the following repair:
Repair the connectors and/or the wiring, or replace
the connectors and/or the wiring. Ensure that all of
the seals are c
orrectly in place and ensure that the
connectors are completely coupled.
Use the electr
onic service tool in order to clear all
logged diagnostic codes and then verify that the
repair eliminates the fault.
STOP.
Test Step 2. Ch
eck the Data Link
Terminating
Resistance
A. Disconnect the P1 connector from the ECM.
B. Measure the resistance between P1:20 and P1:21.
Expected Res
ult:
The resistance is between 50 and 70 Ohms.
Results:
•
Result 1 – The
resistance is between 50 and 70
Ohms. This is the correct resistance. The f ault may
be in the connection to other devices on the data
link. Proce
ed to Test Step 3.
•
Result 2 – The resistance is less than 50 Ohms.
There is a sh
ort circuit in the harness.
Repair: Repair the connectors or the harness
and/or repl
ace the connectors or the harness.
Ensure that all of the seals are correctly in place
and ensure t
hat the connectors are completely
coupled.
Use the ele
ctronic service tool in order to clear all
logged diagnostic codes and then verify that the
repair eliminates the fault.
STOP.
•
Result 3 – T
he resistance is between 110 and 130
Ohms. One of the terminating resistors may have
failed.
Repair: Locate the two terminating resistors and
remove the two terminating resistors from the
harness.
Depending on the application, one or both
of the terminating resistors may be located in other
ECM’s on the data link.
Measure the resistance of the two terminating
resistors.
If one of the terminating resistors is incorrect,
replace the fa
ulty terminating resistor.
If the two terminating resistors are between 50 and
70 Ohms, proce
ed to Test Step 4.
•
Result 4 – The resistance is greater than 150
Ohms. There ma
y be a break in the harness.
ProceedtoTestStep3.
Test Step 3. C
hecktheDataLinkWiring
A. Disconnect each of the connectors that connect
other device
s on the data link.
B. Useamultimeterinordertomeasurethe
resistance b
etween P1:20 to each of the CAN+
pins that connect other devices on the data link.
C. Useamultime
ter in order to measure the
resistance between P1:21 to each of the CAN-
pins that connect other devices on the data link.
D. Useamultimeterinordertomeasurethe
resistancebetweenP1:22toeachoftheCAN
SHIELD pins
that connect other devices.
Expected Result:
The resistance of each wire is below 2 Ohms.
Results:
•
OK – The resistance is below 2 Ohms. Proceed
to Test Ste
p4.
•
Not OK – Some resistances are greater than 2
Ohms.
Repair: Repair the connectors or the harness
and/or rep
lace the connectors or the harness.
Ensure that all seals are correctly in place and
ensure tha
t the connectors are completely coupled.
Use the electronic service tool in order to clear all
logged dia
gnostic codes and then verify that the
repair has eliminated the fault.
STOP.
Test Step 4. Check the other Devices on
theJ1939DataLink
A. Use the appropriate service tools in order to
diagnose other devices on the data link.
Expected Result:
The other
devices are working correctly.
To Next Page
Loading...
