Publicidad
Idiomas disponibles
Idiomas disponibles
Condition
Some customers may comment on low mileage vehicles with an automatic transmissions that the shifting may feel too firm (harsh),
slips, or flares. Customers should be advised that the transmission makes use of an adaptive function that will help to refine the
shift feel while driving and improve shift quality.
Correction
The following should be used to determine what steps should be followed within this document. The 8-Speed transmission utilizes
a total of 5 clutches to obtain all the ratios. Utilize the chart within this document to determine which clutch may require additional
adaptive learning.
•
If a transmission replacement was required, reset the adapts using Service Fast Learn. Evaluate the shifts and further
learn pressures and volumes if required.
•
If a customer has a specific shift concern, the Service Fast Learn should be skipped. Complete the driving learn procedure
to further learn pressures and volumes for the complaint shift.
Transmission Adaptive Functions
The Hydra-Matic® 8-Speed RWD transmission utilizes a line pressure and volume control system during upshifts to compensate
for new transmission build variation as well as the normal wear of transmission components. The variation from new and normal
wear of the apply components within the transmission over time can cause shift time (the time required to apply a clutch) to be
longer or shorter than desired.
In order to compensate for these changes, the transmission control module (TCM) adjusts the pressure commands to the various
pressure control (PC) solenoids to maintain the originally calibrated shift timing. The automatic adjusting process is referred to as
"adaptive learning" and it is used to ensure consistent shift feel plus increase transmission durability.
The TCM monitors the A/T input speed sensor (ISS) and the A/T output speed sensor (OSS) during commanded shifts to determine
if a shift is occurring too fast (harsh) or too slow (soft) and adjusts the corresponding PC solenoid signal to maintain the set shift
feel. The purpose of the adapt function is to automatically compensate the shift quality for the various vehicle shift control systems.
The adapt function is a continuous process that will help to maintain optimal shift quality throughout the life of the vehicle.
How to Adapt Your Transmission
Transmission adapts can be reset and relearned on most vehicles through GDS 2 by using the Transmission Service Fast Learn
procedure. This procedure is completed in the service stall and no vehicle driving is required.
To complete the Transmission Service Fast Learn procedure, enter GDS 2 Diagnosis and navigate to:
•
Module diagnostics
•
Transmission Control Module
•
Configuration / Reset Function
•
Transmission Service Fast Learn
Transmission Service Fast Learn is the recommended method to reset and relearn adapts. This procedure is available on all 2016
MY Trucks, Cars and SUVs with 8L45 and 8L90 Automatic Transmissions (RPOs: M5U, M5T, M5N, M5X).
When the Service Fast Learn is complete, perform a test drive and note any soft or harsh shifts.
To improve these complaint shifts further, locate the clutches that need to be learned in the following table below, and perform the
required learning procedure for each clutch listed in the chart. Execute the steps below with the vehicle warmed up on a smooth
level road. The driver may observe a brief pulse behavior or firm shift feel while the transmission is optimizing the clutch learn
characteristics.
Note: The transmission fluid temperature must be between 35°C (95°F) and 95°C (203°F). Drive vehicle under normal conditions
until this temperature range is achieved. If temperature is outside this range the clutches will not be learned.
Supermatic Transmission Controller Kit
TITLE
19371499
IR
AP1
PART NO.
7
30
SHEET
OF
Publicidad
