Transmission Pre-Diagnostic Troubleshooting Procedure

Transmission Pre-Diagnostic Troubleshooting Procedure

For a complete wiring diagram, refer to.

Perform the following steps prior to any diagnostic procedures:

- Many transmission symptoms can be caused by a low fluid level. If the fluid level is low, locate and repair any leaks and fill the transmission to the proper fluid level. Refer to the Service Information for the proper repair and fluid fill procedures.

- Testing should only be performed with the battery fully charged to avoid false diagnosis.

- With the scan tool, check for engine/PCM DTCs. If engine DTCs are present, refer to the driveability category and perform to the appropriate diagnostic procedures before proceeding.

- With the scan tool, check for transmission/TCM DTCs. record all stored, active, and pending DTC information. Diagnose any pending DTC as a matured DTC.

- With the scan tool, read Event Data. Use this data to identify the conditions in which the DTC was set.

• DTC Event Data may exist even if no DTCs are stored. DTC Event Data is only erased by a battery disconnect, reflash, or Quick Learn 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 or the following good trip, 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 event data and reset all learned transmission values to the controllers default values which may temporarily result in erratic shift schedules.

- With the scan tool, perform the Shift Lever Position Test. If the test does not pass, refer to DTC P0706 - Transmission Range Sensor Rationality. P0706

- For gear ratio error DTCs, use the scan tool to read and record the Clutch Volume Index information.

- Use the wiring diagram as a guide, inspect the wiring and connectors related to this circuit and repair as necessary.

- Refer to the When Monitored and Set Conditions for this DTC. DTCs can set at ignition on, at start up, driving under specific conditions, and after controller diagnostic monitors have run.

- Refer to applicable technical service bulletins for controller software update information. Some conditions can be corrected by upgrading the engine/PCM or transmission/TCM controller software.

- Check for any service information tune-ups or service bulletins for any possible causes that may apply.

Did any of the above procedures repair the vehicle?

Yes

• Testing is complete.

• Perform the Transmission verification Test. Refer to => [ Transmission Verification Test ] Transmission Verification Test.

No

• Refer to => Transmission DTC Based Diagnostics and perform the appropriate diagnostic procedure.