GM Service Manual Online
For 1990-2009 cars only

Service Fast Learn Adapts 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, Service Fast Learn Adapts translates it into the adaptive data cells, which the TCM uses for clutch control during shifts. The scan tool provides initiation of the Service Fast Learn Adapts procedure. This procedure is to be used following transmission repair.

The Service Fast Learn Adapts 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 (w/body and TCM) 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 Service Fast Learn Adapts 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 (TFT) is between 70-100°C (158-212°F)
   • Transmission gear selector has been cycled from Park to Reverse 3 times in order to purge air from the reverse clutches.

  1. Use the scan tool to navigate to Service Fast Learn Adapts by selecting the following commands:
  2. 1.1. F1: Transmission Control Module
    1.2. F5: Module Setup
    1.3. F0: Fast Learn Adapts Process

    Note: If at any time during the procedure, required conditions are not met, Service Fast Learn Adapts may abort and the process may need to be started again from the beginning.

  3. Use the scan tool to perform the Service Fast Learn Adapts procedure.
  4. Note: There are 3 stages required to successfully complete the Service Fast Learn Adapts procedure:

    2.1. PARK test setup
    2.2. DRIVE mode
    2.3. REVERSE mode

    These stages are automatically initiated and controlled by the scan tool. As the procedure is being performed, the scan tool data display will provide operator instructions. Follow the scan tool instructions as required. For a brief description of each stage, refer to PARK Test Setup, DRIVE Mode, and REVERSE Mode below.

  5. Once the procedure is complete, shut OFF the engine and power down the TCM. You will lose communication to the scan tool.
  6. Restart the engine. This will complete the Service Fast Learn Adapts procedure.

The following are brief descriptions of each of the 3 different stages.

PARK Test Setup

While the transmission is in PARK, Service Fast Learn Adapts will prepare for test cycles. The test preparation will include the diagnostic criteria checks, safety checks, vehicle status checks, and then will perform internal transmission test preparation functions such as clutch air purging. The scan tool will instruct the operator to select park and apply the brake only.

DRIVE Mode

Warning: Block the wheels before selecting DRIVE. While in DRIVE, if the Scan Tool loses communication or becomes disconnected, the vehicle could move forward. Failure to block the wheels could result in personal injury or property damage.

Once the PARK setup has completed, the scan tool instructs the driver to select DRIVE. Once DRIVE is selected, the TCM engages the individual clutches to learn the clutch volume, full feed fill thresholds, and pressure offsets. The TCM will only cycle through this test once. Running the Service Fast Learn Adapts procedure multiple times will give the same results and is not necessary.

REVERSE Mode

Warning: Block the wheels before selecting REVERSE. While in REVERSE, if the Scan Tool loses communication or becomes disconnected, the vehicle could move backward. Failure to block the wheels could result in personal injury or property damage.

Next, the scan tool instructs the driver to select REVERSE. The TCM engages the individual clutches to learn the clutch volume, full feed fill thresholds, and pressure offsets. The TCM will only cycle through this test one time. Running the Service Fast Learn Adapts procedure multiple times will give the same results.

Note: When the Service Fast Learn Adapts procedure is completed, the transmission will remain in a neutral state.

Troubleshooting

If the Service Fast Learn Adapts will not run and the above stated conditions have been met, ensure the following:

    •  TFT is between 70-100°C (158-212°F).
    • Brakes and brake switch are functioning properly.
    • No active DTCs.
    • Closed throttle and engine RPM increases above 1500 RPM while in Park Test Setup or at entrance of the test modes.
    • Park/Neutral position switch is properly adjusted and functioning.
    • Line pressure control is able to provide 1000 kPa and is within specifications.
    • Vehicle is not moving, or vibrating excessively.
    • Clutches are properly assembled.