Diagnostic Test

CHECK IF THE DTC IS ACTIVE
1. With the scan tool, read Transmission DTCs.
  Is the status Active for this DTC?
  
  Yes
  - Go To 2.
  No
  - Go To 4.
CHECK FOR OTHER DTCS
1. With the scan tool, read Transmission DTCs.
  Is the DTC U1146-LOST COMMUNICATION WITH EXTERNAL MEMORY also present?
  
  Yes
  - Refer to DTC INDEX and perform the appropriate diagnostic procedure.
  No
  - Go To 3.
CHECK THE TCM
Has the Transmission Control Module (TCM), the CV Transmission been replaced, or a Transmission relearn procedure been performed?

Yes
- Cycle the ignition off for 5 seconds and then back on. Erase the DTC and cycle the ignition again. If the DTC still remains active, check the Transmission Control Module (TCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. Check for any Service Bulletins for possible causes that may apply. If no problems are found, replace the TCM in accordance with the Service Information.
- Refer to STANDARD PROCEDURE and perform the CVT 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. Check for any Service Bulletins for possible causes that may apply. If no problems are found, replace the TCM in accordance with the Service Information.
- Refer to STANDARD PROCEDURE and perform the CVT VERIFICATION TEST.
CHECK THE WIRING AND CONNECTORS
1. If the DTC is not active, erase the DTC and refer to STANDARD PROCEDURE and perform the CVT VERIFICATION TEST.
  Did the DTC P1679-CALIBRATION NOT LEARNED reset?
  
  Yes
  - Go To 2.
  No
  - Test Complete.