68RFE Pre-Diagnostic Troubleshooting Procedure

68RFE PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE

For a complete wiring diagram refer to Diagrams/Electrical. Electrical Diagrams


NOTE: This vehicle uses an NGC4 Control Module (which only controls Transmission operation) and an Engine Control Module (ECM) that controls the Diesel engine. In these procedures, the NGC4 Control Module is referred to as the Powertrain Control Module (PCM).


Perform the following before attempting any diagnostic procedures:
- With the scan tool check pinion factor (if equipped) for proper tire identification and program or reprogram if necessary.
- Check the transmission fluid level. If the fluid level is low, locate and repair any leaks and fill the transmission to the proper level. Refer to the appropriate Service Information for procedures. Many transmission symptoms can be caused by a low fluid level.
- Check the battery. To avoid false diagnosis, testing should only be performed with the battery fully charged.
- With the scan tool, read Engine (ECM) DTCs. If DTCs are present, refer to the Driveability Category and perform to the appropriate diagnostic procedure(s) before proceeding.
- With the scan tool, read Transmission (PCM) DTCs. Record all Stored, Active, and Pending DTC information. Diagnose any Pending DTC as a matured DTC.
- With the scan tool, read and record the DTC EVENT DATA. Use this data to identify the conditions in which the DTC was set.

- NOTE: DTC Event Data may exist even if no DTCs are stored. DTC Event Data is only erased by a Battery Disconnect, reflash, or QuickLearn procedure. Clearing DTCs does NOT erase the DTC Event Data. Some DTCs require two "bad trips" before they are stored (and the MIL illuminates). The transmission may enter "limp-in" mode during the first "bad trip," but if the fault condition is not present after the vehicle is restarted, the pending DTC may be cleared without lighting the MIL. Nevertheless, the DTC Event Data for the pending DTC will remain stored and can still be retrieved with the scan tool. If the customer reports a "limp-in" event but no DTCs are present, check the DTC Event Data.

- Performing a Battery Disconnect will clear all DTC EVENT DATA and reset all learned Transmission values to the default values, which may temporarily result in erratic shift schedules.
- With the scan tool, perform the Shift Lever Position Test. If the test fails with an error code, refer to the diagnostic procedure for P0706 Transmission Range Sensor Rationality. If the test fails without an error code, adjust the shift linkage. P0706
- For Gear Ratio Error DTCs or shift quality complaints, use the scan tool to view CVI Monitor data. Read and record the Clutch Volume Index information.
- Use the wiring diagram as a guide. Inspect the wiring and connectors related to this circuit. Repair as necessary.
- Refer to the When Monitored and Set Conditions for this DTC. DTCs can set at ignition on, at start up, after driving under specific conditions and after diagnostic monitors have been run.
- Refer to applicable Technical Service Bulletins (TSBs) for controller software update information. Some conditions can be corrected by upgrading the Engine (ECM) or Transmission (PCM) controller software.
- Refer to any Service Information Tune Ups or Technical Service Bulletins that apply.

Were there any repairs made that fixed the vehicle?

Yes

- Testing complete.
- Perform 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Transmission Verification Test

No

- Refer to the Transmission category and perform the appropriate diagnostic procedure(s).