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:
Front Wheelhouse Liner Replacement (Rear)
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Front Wheelhouse Liner Replacement
Callout
Component Name
Preliminary Procedure
Remove the tire and wheel assembly. Refer to Tire and Wheel Removal and
Installation.
1
Front Wheelhouse Rear Li ...
Automatic Transmission Control Indicator Opening Cover Replacement
Automatic Transmission Control Indicator Opening Cover Replacement
Callout
Component Name
Preliminary Procedure
Remove the front floor console cover. Refer to Front Floor Console Cover
Replacement.
1
...
Drive Range, First Gear Engine Braking (Gen 1)
When the gear selector lever is moved to the Drive (D) range from the Neutral
(N) position, the transmission will provide engine braking. In this operating range,
the normally-low 1234 pressure control solenoid 5 is commanded ON and, in the engine
braking mode, the following changes occur with ...
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