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Home >> Jeep >> 2012 >> Wrangler Sahara, Automatic Trans >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Transmission Control Module (TCM) - Electrical Diagnostics >> DTC Troubleshooting >> P1644-Incorrect Variant/Configuration >> Diagnostic Test
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Diagnostic Test

  1. PERFORM TCM REPLACEMENT PROCEDURE 
    NOTE:

    Controller is programmed with generic software and will not allow the correct vehicle Powertrain management.

    1. With the scan tool, perform the TCM replacement procedure.

      Were you able to update the controller successfully?

      Yes 

      • Test Complete.
      • Refer to STANDARD PROCEDURE  and perform the NAG1 TRANSMISSION VERIFICATION TEST.

      No 

      • Using the schematics as a guide, check the Transmission Control Module (TCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the TCM in accordance with the Service Information.
      • Refer to STANDARD PROCEDURE  and perform the NAG1 TRANSMISSION VERIFICATION TEST.