
RENR9348-01 145
Troubleshooting Section
C. Perform a 45 N (10 lb) pull test on each of the
wires that are a
ssociated with the temperature
sensors.
D. Check the alle
n head screw for each of the
ECM connectors for the proper torque. Refer to
Troubleshooting, “Electrical Connectors - Inspect”
for correct t
orque values.
E. Check the harness and wiring for abrasions and
for pinch poi
nts from each sensor to the ECM.
Expected Result:
All connectors, pins, and sockets are completely
coupled and/or inserted. The harness and wiring are
free of corro
sion, of abrasion, and of pinch points.
Results:
•
OK – The connectors and wiring appear to be OK.
Proceed to Test Step 2.
•
Not OK – There is a problem in the connectors
and/or wiring.
Repair: Repair the connectors or wiring and/or
replace the connectors or wiring. Ensure that all of
the seals ar
e properly in place and ensure that the
connectors are completely coupled.
Verify that
the repair eliminates the problem.
STOP.
Test Step 2. Check for Active Diagnostic
Codes
A. Connect Ca
terpillar Electronic Technician (ET) to
the service tool connector.
B. Restore el
ectrical power to the ECM.
C. Monitor the active diagnostic code screen on Cat
ET. Check a
nd record any active diagnostic codes.
Note: Wait at least 30 seconds in order for the
diagnosti
c codes to become active.
D. Look for an active 03 or 04 diagnostic code.
Expected Result:
No diagno
stic codes are active.
Results:
•
OK – No diagnostic codes are active.
Repair: The problem appears to be resolved.
The problem may
have been related to a faulty
connection in the harness. Carefully reinspect the
connectors and wiring. Refer to Troubleshooting,
“Electrical C
onnectors - Inspect” for additional
information.
STOP.
•
Not OK – A 03 diagnostic code is active at this
time. The ECM
detects an open circuit condition.
ProceedtoTestStep4.
•
Not OK – A 04 di
agnostic code is active at this
time. The ECM detects a short circuit condition.
ProceedtoTestStep3.
Test Step 3. Create an Open C ircuit by
Disconnecting the Sensor Connector
A. Remove elec
trical power from the ECM.
B. Disconnect the suspect sensor from the harness
at the senso
r connector.
C. Restore electrical power to the ECM.
D. Access the “Active Diagnostic Codes” screen on
Cat ET. Check for an active 03 diagnostic code
for the sus
pect sensor.
Note: Wait at least 30 seconds for activation of the
diagnosti
c codes.
E. Remove electrical power from the ECM.
Expected Result:
A 03 diagno
stic code is now active for the suspect
sensor.
Results:
•
OK – A 03 diagnostic code became active after
the sensor
was disconnected.
Repair: There may be a problem with the sensor.
Temporari
ly connect a new sensor to the harness,
but do not install the new sensor in the engine.
Verify that there are no active diagnostic codes for
the senso
r. If there are no active diagnostic codes
for the sensor, permanently install the new sensor.
Clear any logged diagnostic codes.
STOP.
•
Not OK – T
he 04 diagnostic code is still present
while the sensor is disconnected from the harness.
The sensor is OK. There is a problem in the
harness
between the ECM and the sensor
connector. There may be a problem with the ECM.
Leave the suspect sensor disconnected. Proceed
to Test S
tep 5.