P1679

P1679-CALIBRATION NOT LEARNED

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


Theory of Operation


The first time the vehicle is started, the Transmission Control Module (TCM) receives hydraulic calibration data from an external EEPROM (located in the transmission) and stores this information in the EEPROM of the TCM. If there is no stored hydraulic calibration stored in the TCM this DTC will set. It takes one failure to turn on the MIL.


- When Monitored:

Ignition on with a system voltage between 9.0 and 16.0 volts.

- Set Condition:

The TCM is unable to read the hydraulic calibration data stored in the TCM EEPROM for the period of 5.0 seconds.







Always perform the CVT Pre-Diagnostic Troubleshooting procedure before proceeding. CVT - Pre-Diagnostic Troubleshooting Procedure



Diagnostic Test


1. CHECK IF THE DTC IS ACTIVE

With the scan tool, read Transmission DTCs.

Is the status Active for this DTC?

Yes

- Go To 2

No

- Go To 4



2. CHECK FOR OTHER DTCS

With the scan tool, read Transmission DTCs.

Is the DTC U1146-LOST COMMUNICATION WITH EXTERNAL MEMORY also present?

Yes

- Refer to the diagnostics for U1146-LOST COMMUNICATION WITH EXTERNAL MEMORY. U1146

No

- Go To 3



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.
- Perform CVT VERIFICATION TEST. Verification Tests

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.
- Perform CVT VERIFICATION TEST. Verification Tests



4. INTERMITTENT WIRING AND CONNECTORS

If the DTC is not active, erase the DTC and perform the CVT VERIFICATION TEST. Verification Tests

Did the DTC P1679-CALIBRATION NOT LEARNED reset?

Yes

- Go To 2

No

- Test Complete.