Chevrolet Sonic Repair Manual: Transmission Adaptive Functions
The 6T30/40/45/50 transmission utilizes a line pressure control system during upshifts to compensate for the normal wear of transmission components. As the apply components within the transmission wear or change over time, shift time (the time required to apply a clutch) increase or decreases. In order to compensate for these changes, the transmission control module (TCM) adjusts the pressure commands to the various PC solenoids, to maintain the originally calibrated shift timing. The automatic adjusting process is referred to as ?daptive 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 pressure control (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.
Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn the ignition to LOCK/OFF
in each shift lever position.
For automatic transmission vehicles, the ignition should turn to LOCK/OFF
onl ...
Transmission Assemble (Gen 1)
Special Tools
3-9506289 Universal Adapter
R-0007758 Holding Fixture
S-9407197 Differential Rotating Tool
S-9407198 Differential Bearing Race Wrench
For equivalent regional tools, refer ...
Other materials:
Battery Positive Cable Replacement
Removal Procedure
Disconnect the negative battery cable. Refer to Battery Negative Cable
Disconnection and Connection.
Remove the underhood fuse block cover.
Remove the battery positive nut (1) and the battery positive cable (2),
from the underhood fus ...
Inspection/Maintenance System Check
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
Review Diagnostic System Check - Vehicle
for an overview of the diagnostic approach.
Diagnostic Procedure Instructions provides
an overview of each diagn ...
Input Shaft Assemble
Special Tools
J-840733 Driver
For equivalent regional tools, refer to Special Tools.
Note: Ensure the input shaft rear bearing retaining ring (2) is
placed on the input shaft before installing the input shaft rear bearing
assembly (1).
Place the input sh ...
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