Page 4041 of 5267
C1407- TRANSFER CASE BRAKE CONTROL CIRCUIT LOW
For a complete wiring diagramRefer to Section 8W
Page 4042 of 5267

When Monitored:
With the ignition on and no system undervoltage or overvoltage condition present.
Set Condition:
The Totally Integrated Power Module (TIPM) detects that the Transfer CaseBrake circuit input is low when
output is off.
Possible Causes
(T300) T-CASE MOTOR BRAKE CIRCUIT OPEN
(T300) T-CASE MOTOR BRAKE CIRCUIT SHORTED TO GROUND
TRANSFER CASE MOTOR ASSEMBLY
TOTALLY INTEGRATED POWER MODULE (TIPM)
Diagnostic Test
1.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 GROUND
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 resistance between ground and the (T300) Transfer Case
Motor Brake Signal circuit.
Is the resistance below 5.0 ohms?
Ye s>>
Repair the (T300) Transfer Case Motor Brake Signal 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 3
Page 4043 of 5267

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 .
Page 4044 of 5267
C1408-TRANSFER CASE BRAKE CONTROL CIRCUIT HIGH
For a complete wiring diagramRefer to Section 8W
Page 4045 of 5267

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
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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 .
Page 4047 of 5267
C140B- TRANSFER CASE MOTOR CONTROL CIRCUIT LOW
For a complete wiring diagramRefer to Section 8W
Page 4048 of 5267

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