Control System
Control System Diagram
Shift Control
The transmission gear is shifted according to the shift pattern selected by the driver. In shifting gears, the gear ratio is controlled by the ON/OFF signal using the shift solenoid A and the shift solenoid B.
Band Apply Control
The band apply is controlled when in the 3-2 downshift (engine overrun prevention) and the garage shift (shock control).
The band apply solenoid is controlled by the signal from the Pulse Width Modulation (PWM) to regulate the flow of the oil.
Torque Converter Clutch Control (Electronically Controlled Capacity Clutch = ECCC)
The clutch apply is controlled by moving the converter clutch valve by commanding Torque Converter Clutch (TCC) solenoid using the PWM signal.
Line Pressure Control
The throttle signal allows the current signal to be sent to the force motor. After receiving the current signal, the force motor activates the pressure regulator valve to regulate the line pressure.
On-Board Diagnostic System
Several malfunction displays can be stored in the Powertrain Control Module (PCM) memory, and read out of it afterward.
The serial data lines, which are required for the testing of the final assembly and the coupling to other electronic modules, can be regulated by this function.
Fail Safe Mechanism
If there is a problem in the transmission system, the PCM will go into a "backup" mode.
The vehicle can still be driven, but the driver must use the select lever to shift gears.
Torque Management Control
The transmission control side sends the absolute spark advance signal to the engine control side while the transmission is being shifted. This controls the engine spark timing in compliance with the vehicle running condition to reduce the shocks caused by the change of speed.
ATF Warning Control
The oil temperature sensor detects the ATF oil temperature to control the oil temperature warning, TCC, and the winter mode.
Reverse Lock Out Control
With the selector lever in reverse position, the PCM will not close the PWM solenoid until the vehicle is below 11 km/h (6.8 mph), thus preventing reverse engagement above this speed.
Downhill Control
This mode is automatically activated from "NORMAL" mode only when downhill conditions are recognized.
The shift pattern is identical to "NORMAL" mode except 3-4 and 4-3 shift lines at low throttle modified to get engine braking on a larger speed range.
ECCC lines unchanged compared to "NORMAL" mode.
Uphill Control
When Uphill condition are recognized the 2-3 and 3-4 shift and TCC apply take place only when the engine torque is sufficient in order to avoid shift hunting.
Shift Mode Control
Gear Shift Control
Winter Drive Mode
1. Operation
The winter switch will operate when switched on after all of the following conditions are present:
Conditions:
a. The select lever position is "D" range only.
b. Vehicle speed is 7 mph (11 km/hr) or less.
c. Transmission oil temperature is 130°C (266°F) or less.
d. Accelerator opening is at 8% or less.
2. Cancel Release
1. Cancellation by driver
a. Turning off the winter drive mode switch
b. Shifting select position to "3", "2", or "L" (winter drive mode is not canceled by selecting "N", "R", or "P").
c. Ignition key is turned off.
2. Automatic cancellation
a. When vehicle runs at 21 mph (34 km/hr) or more for 1 second or more
b. When transmission oil temperature reaches 130°C (266°F) or above
Note: The mode returns to normal drive mode or power drive mode after the winter drive mode is canceled.
Backup Mode
If a major system failure occurs which could affect safety or damage the transmission under normal vehicle operation, the diagnostic system detects the fault and overrides the Powertrain Control Module (PCM).
The "CHECK TRANS" light flashes to alert the driver, and the transmission must be manually shifted as follows:
Shifts are firmer to prevent clutch slip and consequent wear. The fault should be corrected as soon as possible.
Functions of Input / Output Components