Automatic Transmission Control System

Description and Operation

Description

The automatic transmission control system relies on various measurements to determine the current control state and calculate the required compensation values. These values are used to control the actuators and achieve the desired control output.

Control System Components

Shift-By-Wire (SBW) System Components

▶ Operating Principle

• Instead of a cable, the system uses electronic signals to shift between P-R-N-D positions.

• The system is designed so that the vehicle is always held in Park when the power is off.

Repair Procedures

Adjustment

TCM Adaptive Value Learning

• TCM adaptive value learning: Perform TCM learning when a shift shock occurs or when related parts are replaced, including the transmission.

• TCM relearn is required in the following cases.

• Replacement of Automatic Transmission Assembly

• TCM Upgrade or Replacement

• Solenoid Valve Replacement

TCM adaptive value learning procedure: Repeat the above procedure at least five times, as shown in the figure below.

• Static Relearning (Condition: ATF temperature 35–95 °C

  

• Driving Learning

1. 1

   Drive the vehicle through all gears in D range. Accelerate from standstill to 1st, 2nd to 3rd, 4th to 5th, 6th to 7th, and 7th to 8th with the throttle fully open.

2. 2

   Downshift from 8th to 7th, 7th to 6th, 6th to 5th, 5th to 4th, 4th to 3rd, 3rd to 2nd, and 2nd to 1st.