
RENR5622 143
Troubleshooting Section
Note: Wait at least 30 seconds in order for the
diagnostic cod
es to become active.
a. Disconnect the following sensors one at a time:
•
Aftercooler temperature sensor (rear)
•
Aftercooler t
emperature sensor (front)
•
Atmospheric pressure sensor
•
Coolant temperature sensor
•
Crankcase pre
ssure sensor
•
Filtered engine oil pressure sensor
•
Turbocharger outlet pressure sensor
•
Left turbocha
rger inlet pressure sensor
•
Right turbocharger inlet pressure sensor
•
Unfiltered engine oil pressure sensor
B. Remove electr
ical power from the ECM.
Expected Result:
The diagnostic code deactivates when a particular
sensor is disconnected.
Results:
•
OK – The 262-03
or 262-04 diagnostic
code deactivates when a particular sensor is
disconnected.
Repair: Connect the suspect sensor. If the code
returns, replace the sensor. Connect all of the
connectors.
Verify that the problem is res olved.
STOP.
•
Not OK – The 262-03 or 262-04 diagnostic
code remains active after all of the sensors are
disconnect
ed. Leave the sensors disconnected.
The sensors are not the cause of the diagnostic
code.ProceedtoTestStep4.
Test Step 4. Check the 5 Volt Supply
Voltages at th e ECM
A. Disconnec
t the J1/P1 ECM connector.
B. Fabricate four jumper wires that are long enough
to be used t
o measure the supply voltage at the
ECM connectors. Crimp connector sockets to one
end of each jumper wire.
C. Remove the wires from terminal locations P1-2 (5
V sensor supply) and P1-3 (sensor return). Install
ajumperwi
re into each of these terminal locations.
D. Remove the wires from terminal locations P2-18
(5 V sensor supp
ly) and P2-35 (sensor return).
Install a jumper wire into each of these terminal
locations.
E. Connect the J1/P1 ECM connector.
F. Restore elect
rical power to the engine ECM.
G. Measure the voltage between the jumper wire in
P1-2 (5 V senso
r supply) and the jumper wire in
P1-3 (sensor return).
H. Measure the v
oltage between the jumper wire in
P2-18 (5 V sensor supply) and the jumper wire in
P2-35 (sensor return).
I. Remove electrical power from the ECM.
Expected Res
ult:
Each voltage measurement is 5.0 ± 0.2 VDC.
Results:
•
OK – The volta
ge measurement is 5.0 ± 0.2 VDC.
The ECM is operating correctly.
Repair: One o
f the supply wires is shorted to
another wire in the harness or one of the supply
wires is shorted to engine ground. To isolate
the problem
to a specific harness, perform the
following test steps:
1. One at a time
, reinstall the wiring for each 5 V
supply while you check Cat ET for an active
262-03 or 262-04 diagnostic code.
a. Disconnect the ECM connector.
b. Install th
e wires that were removed for the
5 V supply at the ECM connector. Refer to
Illustration 67 for wiring information.
c. Connect the ECM connector.
d. Restore el
ectrical power to the engine ECM.
e. Monitor the active diagnostic code screen on
Cat ET. Che
ckforanactive262-03codeor
an active 262-04 code.
Note: Wai
t at least 30 seconds in order for the
diagnostic codes to become active.
f. If a diagn
ostic code becomes active for
this 5 V supply, there is a problem in this
harness between the ECM and the sensor
connecto
r.