3.ACTUATE T-CASE MOTOR
Reconnect the TIPM C4 harness connector.
Ignition on, engine not running.
With the scan tool, actuate the T-Case Motor Brake.
Using a 12-volt test light connected to 12-volts, check the (T300) Trans-
fer Case Motor Brake Signal circuit at the Shift Motor/Mode Sensor
Assembly harness connector.
NOTE: Compare the brightness to that of a direct connection to
the battery.
Does the test light illuminate brightly?
Ye s>>
Replace the Totally Integrated Power Module (TIPM) 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 4
4.(T300) TRANSFER CASE MOTOR BRAKE SIGNAL CIRCUIT OPEN
Turn the ignition off to the lock position.
Disconnect the TIPM C4 harness connector.
Measure the resistance of the (T300) Transfer Case Motor Brake Signal
circuit between the TIPM C4 harness connector and the Shift Motor/
Mode Sensor Assembly harness connector.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (T300) Transfer Case Motor Brake Signal circuit
for an open circuit or high resistance.
Perform the TRANSFER CASE VERIFICATION TEST-VER
1. (Refer to 21 - TRANSMISSION/TRANSAXLE/TRANSFER
CASE - STANDARD PROCEDURE)
No>>
Replace the Totally Integrated Power Module (TIPM) in
accordance with the Service Information.
Perform the TRANSFER CASE VERIFICATION TEST-VER
1. (Refer to 21 - TRANSMISSION/TRANSAXLE/TRANSFER
CASE - STANDARD PROCEDURE)
5.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 .
When Monitored:
With the ignition on and no system undervoltage or overvoltage condition present.
Set Condition:
The Totally Integrated Power Module (TIPM) detects voltage on the Transfer Case Brake circuit when the out-
put is off.
Possible Causes
(T300) T-CASE MOTOR BRAKE CIRCUIT OPEN
(T300) T-CASE MOTOR BRAKE CIRCUIT SHORTED TO POWER
TRANSFER CASE MOTOR ASSEMBLY
TOTALLY INTEGRATED POWER MODULE (TIPM)
Diagnostic Test
1.CHECK IF THE DTC IS ACTIVE
Start the engine and allow it to idle.
Move the Transfer Case Selector Switch to each position several times.
With the scan tool, read the TIPM DTCs.
Is the status Active for this DTC?
Ye s>>
Go to 2
No>>
Go to 5
2.(T300) TRANSFER CASE MOTOR BRAKE SIGNAL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off to the lock position.
Disconnect the Shift Motor/Mode Sensor Assembly harness connector.
Disconnect the TIPM C4 harness connector.
Measure the voltage of the (T300) Transfer Case Motor Brake Signal
circuit.
Is there any voltage present?
Ye s>>
Repair the (T300) Transfer Case Motor Brake Signal 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
3.(T300) TRANSFER CASE MOTOR LOCK SIGNAL CIRCUIT SHORTED TO THE (A918) FUSEDBATTERY
SUPPLY CIRCUIT
Measure the resistance between the (T300) Transfer Case Motor Brake
Signal circuit and the (A918) Fused Battery Supply circuit.
Is the resistance below 5.0 ohms?
Ye s>>
Repair the (T300) Transfer Case Motor Brake Signal circuit.
Perform the TRANSFER CASE VERIFICATION TEST-VER
1. (Refer to 21 - TRANSMISSION/TRANSAXLE/TRANSFER
CASE - STANDARD PROCEDURE)
No>>
Go to 4
4.TRANSFER CASE MOTOR BRAKE
Turn the ignition off to the lock position.
Reconnect the Shift Motor/Mode Sensor Assembly harness connector.
Reconnect the TIPM C4 harness connector.
Ignition on, engine not running.
With the scan tool, clear TIPM DTCs.
With the scan tool, select View DTCs.
Does the DTC P1408–Transfer Case Brake Control Circuit High reset?
Ye s>>
Replace the Transfer Case Motor Assembly in accordance with the Service Information.
Perform the TRANSFER CASE VERIFICATION TEST-VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/TRANSFER CASE - STANDARD PROCEDURE)
No>>
Replace the Totally Integrated Power Module (TIPM) in accordance with theService Information.
Perform the TRANSFER CASE VERIFICATION TEST-VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/TRANSFER CASE - STANDARD PROCEDURE)
5.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 .
When Monitored:
Ignition on. Battery voltage between 9.0 and 16.0 volts.
Set Condition:
Totally Integrated Power Module (TIPM) detects low voltage on the Transfer Case Motor Control circuit for a
period of 0.5 seconds.
Possible Causes
(T101) SHIFT MOTOR CONTROL A CIRCUIT SHORTED TO GROUND
(T102) SHIFT MOTOR CONTROL B CIRCUIT SHORTED TO GROUND
(T101) SHIFT MOTOR CONTROL A CIRCUIT SHORTED TO THE (T102) SHIFT MOTOR CONTROL B CIRCUIT
SHIFT MOTOR/MODE SENSOR ASSEMBLY
TOTALLY INTEGRATED POWER MODULE (TIPM)
Diagnostic Test
1.DTC IS ACTIVE
Ignition on, engine not running.
With the scan tool, read TIPM DTCs.
Is the status Active for this DTC?
Ye s>>
Go to 2
No>>
Go to 9
2.SHIFT MOTOR HARNESS CIRCUIT RESISTANCE
Turn the ignition off to the lock position.
Disconnect the TIPM C4 harness connector.
Measure the resistance between the (T101) Shift Motor Control A circuit
and the (T102) Shift Motor Control B circuit.
Is the resistance between 40 and 100 ohms?
Ye s>>
Go to 8
No>>
Go to 3
3.SHIFT MOTOR CIRCUIT RESISTANCE
Disconnect the Shift Motor/Mode Sensor Assembly harness connector.
Measure the resistance between the (T101) Shift Motor Control A circuit and the (T102) Shift Motor Control B circuit
at the Shift Motor/Mode Sensor Assembly component side.
Is the resistance between 40 and 100 ohms?
Ye s>>
Go to 4
No>>
Go to 7
When Monitored:
Ignition on, battery voltage between 9.0 and 16.0 volts.
Set Condition:
The TIPM detects 16.0 to 18.0 volts on the Transfer Case Motor Control Circuit for 2 seconds.
Possible Causes
(T101) SHIFT MOTOR CONTROL A CIRCUIT SHORTED TO VOLTAGE
(T102) SHIFT MOTOR CONTROL BCIRCUIT SHORTED TO VOLTAGE
(T101) SHIFT MOTOR CONTROL A CIRCUIT SHORTED TO (T102) SHIFT MOTOR CONTROLB CIRCUIT
SHIFT MOTOR/MODE SENSOR ASSEMBLY
TOTALLY INTEGRATED POWER MODULE (TIPM)
Diagnostic Test
1.DTC IS ACTIVE
Ignition on, engine not running.
With the scan tool, read TIPM DTCs.
Is the status Active for this DTC?
Ye s>>
Go to 2
No>>
Go to 9
2.SHIFT MOTOR HARNESS CIRCUIT RESISTANCE
Turn the ignition off to the lock position.
Disconnect the TIPM C4 harness connector.
Measure the resistance between the (T101) Shift Motor Control A circuit
and the (T102) Shift Motor Control B circuit.
Is the resistance between 40 and 100 ohms?
Ye s>>
Go to 8
No>>
Go to 3
3.SHIFT MOTOR RESISTANCE
Disconnect the Shift Motor/Mode Sensor Assembly harness connector.
Measure the resistance between the (T101) Shift Motor Control A circuit and the (T102) Shift Motor Control B circuit
at the Shift Motor/Mode Sensor Assembly component side.
Is the resistance between 40 and 100 ohms?
Ye s>>
Go to 4
No>>
Go to 7
When Monitored:
Ignition on, battery voltage between 9.0 and 16.0 volts.
Set Condition:
The TIPM detects no voltage on the Transfer Case Motor Control circuit for aperiod greater than 2 seconds,
when voltage should be present.
Possible Causes
(T101) SHIFT MOTOR CONTROL A CIRCUIT OPEN
(T102) SHIFT MOTOR CONTROL B CIRCUIT OPEN
SHIFT MOTOR/MODE SENSOR ASSEMBLY
TOTALLY INTEGRATED POWER MODULE (TIPM)
Diagnostic Test
1.DTC IS ACTIVE
Ignition on, engine not running.
With the scan tool, read TIPM DTCs.
Move the Shift control to each position, while monitoring the Data Displayon the scan tool.
Does the DTC reset?
Ye s>>
Go to 2
No>>
Go to 8
2.SHIFT MOTOR HARNESS CIRCUIT RESISTANCE
Turn the ignition off to the lock position.
Remove the TIPM C4 harness connector.
Measure the resistance between the (T101) Shift Motor Control A circuit
and the (T102) Shift Motor Control B circuit.
Is the resistance between 40 and 100 ohms?
Ye s>>
Go to 7
No>>
Go to 3
3.SHIFT MOTOR CIRCUIT RESISTANCE
Disconnect the Shift Motor/Mode Sensor Assembly harness connector.
Measure the resistance between the (T101) Shift Motor Control A circuit and the (T102) Shift Motor Control B circuit
at the Shift Motor/Mode Sensor Assembly component side.
Is the resistance between 40 and 100 ohms?
Ye s>>
Go to 4
No>>
Go to 6
When Monitored:
The ignition on, with the T-Case Switch in a 4W/LO position.
Set Condition:
The TIPM detects the Front Axle Lock Control circuit is shorted low.
Possible Causes
(G304) FRONT AXLE LOCK CONTROL CIRCUIT SHORTED TO GROUND
FRONT AXLE DISCONNECT (FAD) MODULE
TOTALLY INTEGRATED POWER MODULE (TIPM)
Diagnostic Test
1.ACTIVE DTC
CAUTION: Before removing the TIPM harness connectors, clean the connector and locking cam area of dirt
and debris. Failure to do so can result in the connector being jammed or damage to the locking cams on
the harness connector or module. Do not force the assist arm when releasingor installing the harness con-
nector.
Ignition on, engine not running.
With the scan tool, read the TIPM DTCs.
Is the status Active for this DTC?
Ye s>>
Go To 2
No>>
Go To 6
2.(G304) FRONT AXLE LOCK CONTROL CIRCUIT
Turn the ignition off to the lock position.
Disconnect the FAD harness connector.
Ignition on, engine not running.
With the scan tool, actuate the Front Axle Lock Control in the TIPM.
Using a 12-volt test light connected to 12-volts, check the (G304) Front Axle Lock Control circuit in the FAD harness
connector.
Does the test light illuminate brightly?
Ye s>>
Go To 5
No>>
Go To 3
3.(G304) FRONT AXLE LOCK CONTROL CIRCUIT SHORTED TO GROUND
Turn the ignition off to the lock position.
Disconnect the TIPM C2 harness connector.
Measure the resistance between ground and the (G304) Front Axle
Lock Control circuit.
Is the resistance below 5.0 ohms?
Ye s>>
Repair the (G304) Front Axle Lock Control 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 4
4.TOTALLY INTEGRATED POWER MODULE (TIPM)
Using the wiring diagram/schematic as a guide, inspect all wiring and connectors that pertain to this circuit.
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>>
Replace the Totally Integrated Power Module (TIPM) in accordance with theService Information.
Perform the TRANSFER CASE VERIFICATION TEST-VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/TRANSFER CASE - STANDARD PROCEDURE)
5.FRONT AXLE DISCONNECT (FAD) MODULE
Using the wiring diagram/schematic as a guide, inspect all wiring and connectors that pertain to this circuit.
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>>
Replace the Front Axle Disconnect (FAD) Module in accordance with the Service Information.
Perform the TRANSFER CASE VERIFICATION TEST-VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/TRANSFER CASE - STANDARD PROCEDURE)