Diagnostic Test

CHECK RELATED TCM AND COMPONENT CONNECTIONS 

1. Perform any Service Bulletins that apply.
2. Disconnect all TCM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. 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.
   • Terminals that have been pushed back into the connector cavity.
   • Check for spread terminals and verify proper terminal tension.

   Repair any conditions that are found.

6. Reconnect all TCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
11. With the scan tool, read DTCs.

    Did the DTC return?

    Yes 

    • Replace and program the TCM in accordance with the Service Information. Refer to MODULE, TRANSMISSION CONTROL (TCM), REMOVAL AND INSTALLATION .
    • Perform the F21-250 Gen III VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .

    No 

    • Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .