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. |
- Use the scan tool to navigate to Service Fast Learn Adapts by selecting
the following commands:
1.1. | F3: Special Function |
1.2. | F1: Transmission Output Controls |
1.3. | Service Fast Learn Adapts |
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.
- Use the scan tool to perform the Service Fast Learn Adapts procedure.
Note: There are 3 stages required to successfully complete
the Service Fast Learn Adapts procedure:
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.
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 engauges 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 engauges
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.
3. Once the procedure is complete, shut OFF the engine and power down the TCM.
You will lose communication to the scan tool.
4. Restart the engine. This will complete the Service Fast Learn Adapts procedure.
Troubleshooting
If the Service Fast Learn Adapts will not run and the above stated conditions
have been met, make sure the following:
• | TFT is between 70-100°C (158-212°F). |
• | Brakes and brake switch are functioning properly. |
• | 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. |