Diagnostic Test

READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN
1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. With the scan tool, run a Vehicle Scan Report, or record the Environmental Data.
3. With the scan tool, erase DTCs.
4. Turn the ignition off for at least 10.0 seconds.
5. Turn the ignition on.
6. Using the recorded Environmental Data and the When Monitored Conditions above, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read 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 AMBIENT AIR TEMPERATURE (AAT) SENSOR VALUE
1. With the scan tool, read the AAT Sensor value in the Body Control Module (BCM) data list.
Is the ambient air temperature value accurate?

Yes
- Go To 3
No
- Check the AAT Sensor circuits for an open, high resistance, and shorts. If no problems are found, replace the AAT Sensor in accordance with the Service Information.
- Perform the TRANSFER CASE VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK TRANSFER CASE FLUID LEVEL
1. Check the Transfer Case fluid level in accordance with the Service Information. Refer to the appropriate service information .
Is the fluid at the correct level?

Yes
- Go To 4
No
- Check the Transfer Case for leaks and fill to the proper level.
- Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
CHECK DRIVELINE COMPONENT OPERATION
1. Raise and support the vehicle with all four wheels off the ground. Refer to HOISTING, STANDARD PROCEDURE .
2. Start the engine, place the transfer case in 4WD HI and shift Transmission into DRIVE.
  NOTE:
  All four wheels should be spinning at the same speed.
3. Shift the Transfer Case into 4WD LOW in accordance with the Owners Service Information
  NOTE:
  All four wheels should be spinning at the same speed.
  
  Do all four wheels spin at the same speed?
  
  Yes
  - Go To 5
  No
  - Repair the affected driveline component in accordance with the Service Information.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
VERIFY DRIVING CONDITIONS
NOTE:
Check with customer on driving terrain (e.g. mud, sand, snow) for set condition. Operating the vehicle in a manner that causes the clutch to engage/disengage too many times is a short time period will also cause this DTC to set.
1. With the scan tool, erase DTCs.
2. Allow the Transfer Case to cool down.
3. Test drive vehicle on dry paved road.
4. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 6
  No
  - Extreme driving conditions caused DTC to set.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
PERFORM A NON-VOLITILE MEMORY RESET AND CHECK FOR THE DTC TO RETURN
1. Turn the ignition on.
2. With the scan tool, erase DTCs.
3. Shift the Transfer case into 2WD.
4. With the scan tool, perform the "Non-Volatile Memory Reset (Clear T-Case Adaptives)" routine.
5. Turn the ignition off for 10 seconds, then turn ignition on. (Do not perform any Transfer Case shifts.)
  NOTE:
  When the ignition is turned back on, the Drivetrain Control Module (DTCM) will perform a Clutch Learn.
6. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 7
  No
  - The Reset and Clutch Learn has corrected the condition.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
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
  - Repair or replace the Transfer Case as necessary in accordance with the Service Information. Refer to REMOVAL AND INSTALLATION REMOVAL AND INSTALLATION .
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .