C1402

C1402-TRANSFER CASE RANGE SELECT SWITCH CIRCUIT HIGH





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. T-CASE SWITCH VOLTAGE ABOVE 4.8 VOLTS
Ignition on, engine not running.
With the scan tool under Instrument Cluster, read the Transfer Case Switch voltage.
Is the voltage above 4.8 volts?
Yes >> 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?
Yes >> Repair the (K77) 5 Volt Selector Switch Supply circuit for a short to voltage.
Perform the TRANSFER CASE VERIFICATION TEST VER-1. Transfer Case Verification Test
No >> Go to 3.
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?
Yes >> Repair the (K977) Mode Select circuit for a short to voltage.
Perform the TRANSFER CASE VERIFICATION TEST VER-1. Transfer Case Verification Test
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 Switch voltage.
Is the voltage equal to 0.0 volts?
Yes >> Replace the Transfer Case Selector Switch.
Perform the TRANSFER CASE VERIFICATION TEST VER-1. Transfer Case Verification Test
No >> Go to 5.
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 Selector Switch harness connector.
Is the resistance above 5.0 ohms?
Yes >> Repair the (K977) Mode Select circuit for an open.
Perform the TRANSFER CASE VERIFICATION TEST VER-1. Transfer Case Verification Test
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?
Yes >> Repair the Transfer Case Selector Switch (Z905) ground circuit for an open.
Perform the TRANSFER CASE VERIFICATION TEST VER-1. Transfer Case Verification Test
No >> Go To 7.
7. INSTRUMENT CLUSTER
Repair
Replace the Instrument Cluster.
Perform the BODY VERIFICATION TEST VER-1, and TRANSFER CASE VERIFICATION TEST VER-1. Transfer Case Verification Test Body Verification Test
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?
Yes >> Repair as necessary.
Perform the TRANSFER CASE VERIFICATION TEST VER-1. Transfer Case Verification Test
No >> Test complete.