
RENR9348-01 93
Troubleshooting Section
g01159881
Illustration 12
Sensor co nnector
(A) Se nsor supply
(B)Sensorreturn
(C) Sens or signal
C. Perform a 45 N (10 lb) pull test on each of the
wires in the ECM connector and on each of the
wires in the pressure sensor connectors.
D. Check the allen head screw for each of the
ECM connectors and the machine connectors
for the proper torque. Refer to Troubleshooting,
“Electrical Connectors - Inspect” for the correct
torque values.
E. Check the harness and wiring for abrasions and
for pinch points from each of the pressure sensors
back to the ECM.
Expected Result:
All connectors, pins and sockets are completely
coupled and/or inserted and the harness and wiring
are free of corrosion, of abrasion or of pinch points.
Results:
•
OK – The harness and connectors appear to be
OK. Proceed to Test Step 2.
•
Not OK – There is a problem with the connectors
and/or wiring.
Repair: Repair the connectors or wiring and/or
replace the connectors or wiring. Ensure that
all of the seals for each of the connectors are
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 Caterpillar Electronic Technician (ET) to
the service tool connector.
B. Restore electrical power to the ECM.
C. Monitor the active diagnostic code screen on Cat
ET. Check for an active 262-03 code and an active
262-04 code.
Note: Wait at least 30 seconds in order for the
diagnostic co
des to become active.
D. Remove electrical power from the ECM.
Expected Result:
No diagnostic
codes are active.
Results:
•
OK – No diagnostic codes are active.
Repair: If any
of the above codes are logged
and the engine is not running properly, refer to
Troubleshooting, “Troubleshooting Without a
Diagnostic C
ode”.
If the engine is running properly at this time, there
maybeaninte
rmittent problem in a harness
that is causing the codes to be logged. Refer to
Troubleshooting, “Electrical Connectors - Inspect”.
STOP.
•
Not OK – Eithe
r the 262-03 or 262-04 diagnostic
code is active at this time. Proceed to Test Step 3.
Test Step 3.
Disconnect the P ressure
Sensors an
d Check for Active Diagnostic
Codes
A. Restore electrical power to the ECM.
B. Monitor the active diagnostic code screen on Cat
ET while you disconnect each pressure sensor
connector
.Checkforanactive262-03codeoran
active 262-04 code.
Note: Wait
at least 30 seconds in order for the
diagnostic codes to become active.
a. Disconne
ct the following sensors one at a time:
•
Engine oil pressure sensor
•
Boost pressure sensor
•
Fuel pres
sure sensor
•
Atmospheric pressure sensor
Remove electrical power from the ECM.