Page 4025 of 5267

5.TRANSFER CASE SELECTOR SWITCH
Turn the ignition off to the lock position.
Connect a jumper wire between the (K77) 5 Volt Selector Switch Supply
circuit and the (K977) Mode Select circuit in the Transfer Case Selector
Switch harness connector.
Ignition on, engine not running.
With the scan tool in Data Display, read the Range Switch voltage.
NOTE: The switch voltage should be approximately 5.0 volts ( ± .05
volts).
Does the voltage display as described?
Ye s>>
Replace the Transfer Case Selector Switch in accordance
with the Service Information.
Perform the TRANSFER CASE VERIFICATION TEST-VER
1. (Refer to 21 - TRANSMISSION/TRANSAXLE/TRANSFER
CASE - STANDARD PROCEDURE)
No>>
Go To 6
6.(K977) MODE SELECT CIRCUIT SHORT TO GROUND
Disconnect the Instrument Cluster C3 connector.
Measure the resistance between ground and the (K977) Mode Select
circuit.
Is the resistance less than 5.0 ohms?
Ye s>>
Repair the (K977) Mode Select circuit for a short to ground.
Perform the TRANSFER CASE VERIFICATION TEST-VER
1. (Refer to 21 - TRANSMISSION/TRANSAXLE/TRANSFER
CASE - STANDARD PROCEDURE)
No>>
Go To 7
Page 4026 of 5267

7.(K977) MODE SELECT CIRCUIT OPEN
Measure the resistance of the (K977) Mode Select circuit between the
Instrument Cluster C3 harness connector and the Transfer Case Selec-
tor Switch harness connector.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (K977) Mode Select circuit for an open.
Perform the TRANSFER CASE VERIFICATION TEST-VER
1. (Refer to 21 - TRANSMISSION/TRANSAXLE/TRANSFER
CASE - STANDARD PROCEDURE)
No>>
Replace the Instrument Cluster in accordance with the Ser-
vice Information.
Perform the BODY VERIFICATION TEST-VER 1 (Refer to 8
- ELECTRICAL/ELECTRONIC CONTROL MODULES -
STANDARD PROCEDURE) and TRANSFER CASE VERI-
FICATION TEST-VER 1 (Refer to 21 - TRANSMISSION/
TRANSAXLE/TRANSFER CASE - STANDARD
PROCEDURE).
8.INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
While monitoring the scan tool data relative to this circuit, wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Were any problems found?
Ye s>>
Repair as necessary.
Perform the TRANSFER CASE VERIFICATION TEST-VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/TRANSFER CASE - STANDARD PROCEDURE)
No>>
Te s t c o m p l e t e .
Page 4027 of 5267
C1402- TRANSFER CASE RANGE SELECT SWITCH CIRCUIT HIGH
For a complete wiring diagramRefer to Section 8W
Page 4028 of 5267

When Monitored:
With the ignition on.
Set Condition:
Transfer Case Range Select Switch voltage greater than 4.86 volts for 5 seconds
Possible Causes
(K77) 5 VOLT SELECTOR SWITCH SUPPLY CIRCUIT SHORTED TO VOLTAGE
(K977) MODE SELECT CIRCUIT SHORTED TO VOLTAGE
(K977) MODE SELECT CIRCUIT OPEN
(Z905) TRANSFER CASE SELECTOR SWITCH GROUND CIRCUIT OPEN
TRANSFER CASE SELECTOR SWITCH
INSTRUMENT CLUSTER
Diagnostic Test
1.TCASE SWITCH VOLTAGE ABOVE 4.8 VOLTS
Ignition on, engine not running.
With the scan tool under Instrument Cluster, read the Transfer Case Switchvoltage.
Is the volage above 4.8 volts?
Ye s>>
Go To 2
No>>
Go to 8
2.(K77) 5 VOLT SELECTOR SWITCH SUPPLY CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off to the lock position.
Disconnect the Transfer Case Selector Switch harness connector.
Disconnect the Instrument Cluster C4 harness connector.
Ignition on, engine not running.
Measure the voltage of the (K77) 5 Volt Selector Switch Supply circuit.
Is there any voltage present?
Ye s>>
Repair the (K77) 5 Volt Selector Switch Supply circuit for a
short to voltage.
Perform the TRANSFER CASE VERIFICATION TEST-VER
1. (Refer to 21 - TRANSMISSION/TRANSAXLE/TRANSFER
CASE - STANDARD PROCEDURE)
No>>
Go to 3
Page 4029 of 5267

3.(K977) MODE SELECT CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off to the lock position.
Disconnect the Instrument Cluster C3 harness connector.
Ignition on, engine not running.
Measure the voltage of the (K977) Mode Select circuit.
Is there any voltage present?
Ye s>>
Repair the (K977) Mode Select circuit for a short to voltage.
Perform the TRANSFER CASE VERIFICATION TEST-VER
1. (Refer to 21 - TRANSMISSION/TRANSAXLE/TRANSFER
CASE - STANDARD PROCEDURE)
No>>
Go to 4
4.TRANSFER CASE SELECTOR SWITCH
Turn the ignition off to the lock position.
Reconnect the Instrument Cluster C3 harness connector.
Reconnect the Instrument Cluster C4 harness connector.
Ignition on, engine not running.
With the scan tool under Instrument Cluster, read the Transfer Case Switchvoltage.
Is the voltage equal to 0.0 volts?
Ye s>>
Replace the Transfer Case Selector Switch.
Perform the TRANSFER CASE VERIFICATION TEST-VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/TRANSFER CASE - STANDARD PROCEDURE)
No>>
Go to 5
Page 4030 of 5267
5.(K977) MODE SELECT CIRCUIT OPEN
Turn the ignition off to the lock position.
Measure the resistance of the (K977) Mode Select circuit between the
Instrument Cluster C3 harness connector and the Transfer Case Selec-
tor Switch harness connector.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (K977) Mode Select circuit for an open.
Perform the TRANSFER CASE VERIFICATION TEST-VER
1. (Refer to 21 - TRANSMISSION/TRANSAXLE/TRANSFER
CASE - STANDARD PROCEDURE)
No>>
Go To 6
6.TRANSFER CASE SELECTOR SWITCH (Z905) GROUND CIRCUIT OPEN
Measure the resistance between ground and the (Z905) Transfer Case
Selector Switch ground circuit.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the Transfer Case Selector Switch (Z905) ground cir-
cuit for an open.
Perform the TRANSFER CASE VERIFICATION TEST-VER
1. (Refer to 21 - TRANSMISSION/TRANSAXLE/TRANSFER
CASE - STANDARD PROCEDURE)
No>>
Go To 7
Page 4031 of 5267
7.INSTRUMENT CLUSTER
Repair
Replace the Instrument Cluster in accordance with the Service Information.
Perform the BODY VERIFICATION TEST-VER 1 (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE) and TRANSFER CASE VERIFICATION TEST-VER 1 (Refer to
21 - TRANSMISSION/TRANSAXLE/TRANSFER CASE - STANDARD PROCEDURE).
8.INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
While monitoring the scan tool data relative to this circuit, wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Were any problems found?
Ye s>>
Repair as necessary.
Perform the TRANSFER CASE VERIFICATION TEST-VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/TRANSFER CASE - STANDARD PROCEDURE)
No>>
Te s t c o m p l e t e .
Page 4032 of 5267
C1404- TRANSFER CASE RANGE POSITION SENSOR CIRCUIT LOW
For a complete wiring diagramRefer to Section 8W