(Table 194, contd)
Troubleshooting Test Steps
Values Results
3. Insert a Jumper at the Suspect Mode Switch
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the suspect mode selection
switch.
C. Fabricate a jumper wire and install the jumper wire across
the two contacts of the suspect switch.
D. Turn the keyswitch to the ON position. Monitor the status
screen on the electronic service tool. Connect the jumper wire
and then disconnect the jumper wire.
E. Turn the keyswitch to the OFF position. Remove the jumper
wire.
Switch status
“CLOSED” with
jumper installed
Result: When the jumper wire is connected, the switch is in
the CLOSED position.
Repair: Replace the suspect mode selection switch.
Use the electronic service tool to clear all logged diagnostic
codes and verify that the repair eliminates the fault.
Result: When the jumper wire is connected, the switch is in
the OPEN position
Proceed to Test Step 4.
4. Measure the Voltage at the Switch
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the mode selection switches.
C. Turn the keyswitch to the ON position.
D. Use the electronic service tool to turn both of the mode
switches to the ON position.
E. Measure the voltage from the input of each mode switch to
a suitable ground.
At least 10 VDC
for a 12 V system
At least 22 VDC
for a 24 V system
Result: One of the measured voltages is not within the ex-
pected range - The fault is in the wiring between the sus-
pect mode switch and the ECM.
Repair: Repair the faulty wiring or replace the faulty wiring.
Use the electronic service tool to clear all logged diagnostic
codes and verify that the repair eliminates the fault.
Result: The measured voltages are within the expected
range.
Proceed to Test Step 5.
5. Check the Wiring for an Open Circuit
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the mode switches.
C. Use a multimeter to measure the resistance between P1:36
and the ground terminal on each of the mode switches.
Less than two
Ohms
Result: One of the measured resistances is greater than
two Ohms - The fault is in the wiring between the suspect
mode switch and P1:36.
Repair: Repair the faulty wiring or replace the faulty wiring.
Use the electronic service tool to clear all logged diagnostic
codes and verify that the repair eliminates the fault.
Result: All measured resistances are less than two Ohms.
Proceed to Test Step 6.
6. Check the Wiring for a Short Circuit
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the mode switches.
C. Disconnect the P1 connector from the ECM.
D. Use a multimeter to measure the resistance between P1:77
and all other terminals on the P1 connector.
E. Use a multimeter to measure the resistance between P1:78
and all other terminals on the P1 connector.
Greater than 1 k
Ohm
Result: One of the measured resistances is less than 1 k
Ohm. The fault is in the wiring between the ECM and the
mode switch.
Repair: Repair the faulty wiring or replace the faulty wiring.
Use the electronic service tool to clear all logged diagnostic
codes and verify that the repair eliminates the fault.
Result: All measured resistances are greater than 100
Ohms. There is a fault in the ECM.
Contact the Dealer Solutions Network (DSN).
354 UENR4469-36
Circuit Tests
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