Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read DTCs and record on the repair order.
2. Record the Environmental Data.
3. With the scan tool, erase DTCs.
4. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
5. With the scan tool, read Drivetrain Control Module (DTCM) DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE SHIFT MOTOR/MODE SWITCH SENSOR OPERATION
1. Turn the ignition off.
2. Disconnect the Shift Motor/Mode Switch Sensor harness connector.
3. Turn the ignition on.
4. Using a 12-volt test light, jump across from the (T315) Shift Motor Control A circuit and the (T316) Shift Control Motor B circuit at the Transfer Case Motor C1 harness connector.
5. With the scan tool, actuate the Shift Motor/Mode Switch Sensor.
  Does the test light illuminate brightly when flashing on and off?
  
  Yes
  - Go To 6
  No
  - Go To 3
CHECK THE (T316) SHIFT CONTROL MOTOR B CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (T316) Shift Control Motor B circuit between the Shift Motor/Mode Switch Sensor C1 harness connector and the DTCM harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (T316) Shift Control Motor B circuit for an open or high resistance.
  - Perform the DTCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE (T315) SHIFT MOTOR CONTROL A CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (T315) Shift Motor Control A circuit between the Shift Motor/Mode Switch Sensor harness connector and the DTCM harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (T315) Shift Motor Control A circuit for an open or high resistance.
  - Perform the DTCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all DTCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Perform a terminal drag test on each connector terminal to verify proper terminal tension.
  Repair any conditions that are found.
5. Reconnect all DTCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read DTCM DTCs.
  Did the DTC return?
  
  Yes
  - Replace the DTCM in accordance with the Service information. Refer to MODULE, DRIVETRAIN CONTROL (DTCM), REMOVAL .
  - Perform the DTCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the DTCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE SHIFT MOTOR/MODE SWITCH SENSOR
NOTE:
Before continuing, check the shift motor/mode switch sensor jumper harness connector terminals for corrosion, damage or terminals push out, repair/replace as necessary.
1. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
  Were any problems found?
  
  Yes
  - Repair the wiring or poor connection.
  - Perform the DTCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Replace Transfer Case Clutch Coil in accordance with Service Information. Refer to COIL, CLUTCH, REMOVAL .
  - Perform the DTCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .