Menu +
Generic selectors
Exact matches only
Search in title
Search in content

TCM

< Previous Next >

2016 – MX-5 – Transmission/Transaxle

TCM

Purpose/Function

  • The TCM detects the vehicle conditions and performs calculations and processing based on input information from each type of sensor and switch.

  • Outputs control signals to each solenoid valve so that each type of control is optimally implemented according to the vehicle conditions.

Function Table

Control item

Main control content

Shift point control

Automatic shift control

(D position)

Driving mode

Normal mode

  • Mode selection during normal driving (without drive selection switch)

  • Normal mode selected using drive selection (with drive selection switch)

  • Performs automatic shift corresponding to vehicle speed and accelerator pedal depression amount

SPORT mode

(with drive selection switch)

  • SPORT mode selected using drive selection

  • Performs automatic shifting corresponding to vehicle speed and accelerator pedal depression amount

  • Lower gear is selected than while in the Normal mode

Active Adaptive Shift (AAS) mode

  • Unnecessary shift up is suppressed for several seconds by maintaining the gear corresponding to the operation speed at which the accelerator pedal is released

  • The optimum gear on the low vehicle-speed side is selected and shift down is executed corresponding to the operation force at which the brake pedal is depressed

  • During cornering, shift up is suppressed in preparation for acceleration after cornering

  • In regions of high elevation, the optimum gear is selected corresponding to the environment

  • The slope is estimated in the TCM to select the appropriate gear for ascent and descent

  • When SPORT mode is selected, the AAS selects a lower gear compared to when normal mode is selected, and maintains it for a longer period of time (with drive selection switch)

Direct mode control

(D range)

  • Direct mode control enables temporary use of manual shifting using the steering shift switch even when the selector lever is in the D range

  • After switching to direct mode, the system returns to automatic shift mode automatically in accordance with driving conditions

Manual shift control

(M position)

  • When M position is selected, manual shifting is prioritized according to the driver’s shift up/shift down operation

Neutral control

  • Shifts to neutral when vehicle is stopped in D range

Reverse control

  • If the selector lever is moved from N to R while the vehicle is traveling and the transmission shifts into reverse, TCM inhibits the transmission from shifting into reverse while traveling.

Shift pressure control

Line pressure control

  • Controls line pressure with high accuracy and fine control corresponding to engine load conditions and vehicle driving conditions

Learning control

  • Learns engine performance changes and transmission deterioration over time to optimally correct clutch engagement pressure

Torque converter clutch (TCC) control, slip control

  • By gradually engaging/disengaging TCC piston, shock during operation is reduced

  • Implements TCC control when accelerator pedal is fully closed for improved fuel economy and emission performance

  • Slip control, by sliding the TCC when TCC is in the off range, extends the TCC range to low vehicle speeds.

Engine-transmission integration control

  • Optimally controls engine output torque when shifting

  • Calculates optimum clutch engagement pressure according to engine output torque

On-board diagnostic system

  • Main part of transmission control includes self-diagnosis function. In case of malfunction, automatic transmission warning light illuminates to alert driver, and DTC is stored in TCM

  • When transmission malfunction is determined resulting from on-board diagnostic test, system control is switched to prevent any dangerous situation while driving

Construction

System wiring diagram

Block diagram

Operation

Input/Output signal and related controls

Component

Control

Automatic shift control

(D position)

Direct mode control

(D range)

Manual shift control

(M position)

Neutral control

Reverse control

Line pressure control

Learning control

Torque converter clutch (TCC) control, slip control

Engine-transmission integration control

On-board diagnostic system

Input

VSS

X

X

X

X

X

X

X

X

Turbine sensor

X

X

X

X

X

X

X

X

X

TR switch

X

X

X

X

X

TFT sensor

X

X

X

X

CAN

M range switch

X

X

Up switch

X

X

Down switch

X

X

Steering shift switch

X

X

X

Brake switch

X

Throttle opening signal (APP sensor)

X

X

X

X

X

X

X

Engine speed signal (Eccentric shaft position sensor)

X

X

X

X

X

X

Engine torque signal (MAF sensor)

X

X

X

X

Engine coolant temperature signal (ECT sensor)

X

X

X

Drive selection signal

X

Wheel speed signal (wheel speed sensor)

X

X

X

Output

ON/OFF type

Shift solenoid A

X

X

X

X

X

Shift solenoid B

X

X

X

X

X

X

Shift solenoid C

X

X

X

X

X

X

Shift solenoid D

X

X

X

X

X

Shift solenoid E

X

X

X

X

X

X

X

Linear type

Line pressure control solenoid

X

X

X

X

X

X

TCC control solenoid

X

X

Shift solenoid F

X

X

X

X

X

X

X

Shift solenoid G

X

X

X

X

X

X

X

CAN

AT warning light

X

X

X

Torque reduction request signal

X

Speedometer signal

Electric AT oil pump driver

X: Available

< Previous Next >

© 2014 Mazda North American Operations, U.S.A.