Troubleshooting

RENR2696-01 197
Troubleshooting Section
Test Step 1. Inspect Electrical Connectors
and Wiring
A. Turn the keyswitch to the OFF position.
B. Thoroughly in
spect J1/P1 ECM connector, and the
J20/P20 MIC. Refer to Troubleshooting, “Electrical
Connectors - Inspect” for details.
C. Perform a 45 N (10 lb) pull test on each of the
wires in the customer connector and the ECM
connector th
at are associated with the diagnostic
lamp. Refer to illustration 109.
D. Check the J1/
P1 ECM connector (Allen head
screw) for the proper torque of 2.25 ± 0.25 N·m
(20±2lbin).
Check the J20/P20 Machine Interface Connector
(MIC) for the proper torque of 6.0 N·m (55 lb in).
E. Check the harness and wiring for abrasions and
for pinch points from the battery to the ECM.
Results:
•
OK – Proceed
to Test Step 2.
•
Not OK
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 tha
t the repair eliminates the problem.
STOP.
Test Step 2. Inspect the Lamp, the Fuse,
and the Power Supply
A. Disconnec
t the lamp from the wiring harness.
Inspect the lamp in order to determine if the lamp
has failed.
B. Measure the resistance across the two terminals
of the lamp. If the resistance is more than 2000
ohms, the
bulb has failed.
C. Check the battery by connecting a test lamp
across th
e terminal of the battery.
Expected Result:
The lamp has less than 2000 ohms and the power
supply is OK.
Results:
•
OK – The la
mp appears to be operating correctly
at this time. Proceed to Test Step 3.
•
Not OK
Repair: Replace the suspect component or repair
the suspect component. Verify that the repairs
have eliminat
ed the problem.
STOP.
Test Step 3. Inspect the Input to the Lamp
at the ECM connector
A. Turn the keys
witch to the ON position.
B. Measure the voltage at the lamp socket.
Expected Result:
The voltage sh
ould be between 12.0 VDC and 24.0
VDC.
Results:
•
OK – The voltage is between 12.0 VDC and 24.0
VDC.
Repair: Replace the bulb.
Verify that the repair eliminates the problem.
Proceed to Te
st Step 4.
•
Not OK – The voltage is not in the range that is
expected. Pr
oceed to Test Step 5.
Test Step 4. Test the Individual Lamp
Circuits
A. Disconnect ECM Connector J1/P1.
B. Insert a 70-
Pin Breakout T between ECM
Connector J1 and ECM Connector P1.
C. Fabricate a
jumper wire 100 mm (4 inch) long.
Crimp a Deutsch pin to both ends of the wire.
D. Insert one e
nd of the jumper wire into the socket
for the driver for the suspect lamp.
E. Ins ert the o
ther end of the jumper wire into the
socket for -battery.
F. Turn the ke
yswitch to the ON position and observe
the lamp.
Expected R
esult:
The diagnostic lamp turns on while the jumper is
connected
to both sockets. Also, the diagnostic lamp
turns off when the jumper is removed from one of
the sockets.