Chevrolet Trax: Transmission adaptive values learn

Transmission Adaptive Values Learn is a procedure for 6 speed automatic transmissions in which a series of tests are run to allow the transmission control module (TCM) to learn individual clutch characteristics. Once the clutch data is learned, Transmission Adaptive Values Learn translates it into the adaptive data cells, which the TCM uses for clutch control during shifts. The scan tool provides initiation of the Transmission Adaptive Values Learn procedure. This procedure is to be used following transmission repair.

The Transmission Adaptive Values Learn procedure must be performed when one of the following repairs have been made to the vehicle. Failure to perform the procedure after one of the following repairs may result in poor transmission performance, as well as transmission DTCs being set:

• Transmission internal service/overhaul
• Valve body repair or replacement
• Control solenoid valve assembly replacement
• TCM software/calibration update
• Any service in response to a shift quality concern

NOTE: Ensure the following conditions are met before performing the Transmission Adaptive Values Learn procedure:

• Drive wheels are blocked
• Parking brake is applied
• Service brake is applied
• Zero percent throttle and no external engine RPM control
• Transmission fluid temperature is between values listed below, if you attempt to run the test above or below these temperatures, the test will not start:

• MY 2011 and prior 70-95ºC (158-203ºF)
• MY 2012 Gen 1 70-95ºC (158-203ºF)
• MY 2012 Gen 2 64-95ºC (147-203ºF)
• MY 2013 Gen 1 70-95ºC (158-203ºF)
• MY 2013 Gen 2 64-76ºC (147-169ºF)
• MY 2014 and later 64-76ºC (147-169ºF)

• Transmission gear selector has been cycled from Park to Reverse 3 times in order to purge air from the reverse clutches.
• Transmission Adaptive Values Learn will abort if the transmission fluid temperature increases to the values listed below:

• MY 2011 and prior 110ºC (230ºF)
• MY 2012 Gen 1 110ºC (230ºF)
• MY 2012 Gen 2 100ºC (212ºF)
• MY 2013 Gen 1 110ºC (230ºF)
• MY 2013 Gen 2 86ºC (187ºF)
• MY 2014 and later 86ºC (187ºF)

NOTE: If at any time during the procedure, required conditions are not met, Transmission Adaptive Values Learn Adapts may abort and the process may need to be started again from the beginning. If this occurs, the transmission will be left in a neutral state until the controller is shut down, key OFF and remove the scan tool and wait for more than 30 seconds prior to re-try procedure. If the procedure repeatedly fails, a limit that engineering set is being exceeded and there is possibly a transmission hardware issue.

1. Use the scan tool to navigate to Transmission Adaptive Values Learn by selecting the following:

1. Module Diagnostics
2. Transmission Control Module
3. Configurations/Reset Functions
4. Transmission Adaptive Values Learn

NOTE: If at any time during the procedure, required conditions are not met, Transmission Adaptive Values Learn may abort and the process may need to be started again from the beginning.

2. Use the scan tool to perform the Transmission Adaptive Values Learn procedure. As the procedure is being performed, the scan tool data display will provide operator instructions. Follow the scan tool instructions, as required.
3. Once the procedure is complete, shut OFF the engine and power down the TCM. You will lose communication to the scan tool.

NOTE: When the Transmission Adaptive Values Learn procedure is completed, the transmission will remain in a neutral state until the controller shuts down. If after 1-2 minutes of sitting, with the key OFF and scan tool removed, the vehicle remains in a neutral state, disconnect the battery and wait 5-10 minutes and then hook the battery back up. Reverse and drive should return.

4. Restart the engine. This will complete the Transmission Adaptive Values Learn procedure.

Troubleshooting

If the Transmission Adaptive Values Learn will not run and the above stated conditions have been met, ensure the following:

NOTE: The generation of transmission can be determined by using a scan tool to check for Specific DTC P0842. If DTC does not show Invalid, the transmission is Gen 1. If DTC shows Invalid, transmission is Gen 2.

• Determine if transmission is Gen 1 or Gen 2.
• Verify vehicle model year.
• Verify transmission fluid temperature is between the temperatures listed above for the vehicle model year and generation of transmission.
• Brakes and brake switch are functioning properly
• No active DTCs
• Closed throttle and engine RPM increases above 1,500 RPM while at entrance of the test
• Park/Neutral position switch is properly adjusted and functioning
• Line pressure control is able to provide 1,000 kPa and is within specifications
• Vehicle is not moving or vibrating excessively
• Clutches are properly assembled

MANUAL MODE OR TAP UP/DOWN DIAGNOSIS

1. If any DTCs are set, diagnose those DTCs first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
2. If the Manual Mode or Tap Up/Down does not function, refer to the Circuit/System Verification for DTC P0815, P0816, or P0826.

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