Diagnostic Test

READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR DTC TO RETURN
NOTE:
The appropriate trailer or a trailer simulator must be present and connected for the results of this test to be valid.
1. Perform any Service Bulletins that may apply.
2. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
3. With the scan tool, read and record the Environmental Data to help identify the conditions in which the DTC was set.
4. For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
5. Cycle the ignition from off to on three times, waiting five seconds between each ignition state.
6. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - The condition that caused the symptom is currently not present. Inspect the related wiring for a possible intermittent condition. Look for any chafed, pierced, pinched, or partially broken wires.
  - Perform the appropriate INTERMITTENT CONDITION diagnostic procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK FOR POWERTRAIN CONTROL MODULE (PCM) OR COMMUNICATION RELATED DTCS
1. Refer to the recorded DTCs.
  Are there any PCM DTCs present?
  
  Yes
  - Perform the applicable diagnostic procedure(s). Refer to DIAGNOSTIC CODE INDEX (6.4L), or refer to DIAGNOSTIC CODE INDEX (6.7L).
  No
  - Go To 3
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect the TRSCM 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. Connect the TRSCM harness connectors. Be certain that the harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect the 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 Event and 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 TRSCM DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Trailer Reverse Steering Control Module (TRSCM) in accordance with Service Information. Refer to MODULE, TRAILER REVERSE STEERING CONTROL (TRSCM), REMOVAL AND INSTALLATION .
  - Perform the TRSCM VERIFICATION TEST. Refer to STANDARD PROCEDURE - TRSCM VERIFICATION TEST .
  No
  - Perform the TRSCM VERIFICATION TEST. Refer to STANDARD PROCEDURE - TRSCM VERIFICATION TEST .
  - Test complete.