Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual — part 365

7A-8 AUTOMATIC TRANSMISSION (AW30-40LE)

CONTROL AND FUNCTIONS

Item Description

Pattern selection control

・ In D range, speed change point and Lock-up point can be

changed by setting pattern selection switch to “POWER” or
“NORMAL”, or “WINTER” (UBS) mode.

Gear shift control
(Speed change point
Speed change timing)

・ Gear shift position in the conditions made up of transmission shift

positions (D.2.L) combined with pattern selection switch
(POWER, NORMAL, and WINTER) can be controlled in
accordance with vehicle speed and the opening of throttle valve.

Lock-up control

・ In D range, 2nd, 3rd, or O/D lock-up is conducted in “POWER” or

“NORMAL” mode.

・ In 2, L range, lock-up is off in the whole area.

・ Lock-up timing is controlled to reduce gear shift shock using kind

of gear shift (shift up, etc.) lock-up status at the time of gear shift
judgement, gear step and throttle opening after gear shift.

・ When the brake is switched on, lock-up is discontinued.

・ Lock-up is prohibited when idling is defected by throttle position

sensor.

Overdrive gear shift control

・ If O/D switch is set on in D range (O/D OFF lamp ON), gear shift

to O/D is not effected.

However, to prevent engine over revolution.

・ 4→3 shifting at vehicle speed is less than 126 km/h (TF), 124

km/h (UBS).

・ 3→4 shifting at vehicle speed is more than 128 km/h (TF), 126

km/h (UBS).

Throttle leaning control

・ Variation in throttle position sensor voltage is corrected in TCM

thereby to ensure a constant gear shift control.

Fail-safe function

・ When trouble occurs to vehicle sensor and each solenoid, TCM

automatically exerts fail-safe control not to spoil driveability.

・ This control is exerted when sensor or actuator is in trouble,

while TCM works normally.

Self-diagnosis function

・ If there is an abnormality in vehicle sensors, each solenoid (S1-

S3), or throttle position sensor, “CHECK TRANS” lamp is
actuated to warn the driver. But when the abnormality items have
been restored to normal, the light does not blink.

・ Faulty parts are memorized in TCM. If self-diagnosis start signal

is inputted, “CHECK TRANS” lamp is blinked and results of
diagnosis are indicated. A history of faults remains recorded even
when IGN switch is off.

Tech 2

・ Output of control data in the TCM

・ Actuator (Solenoid) operation check

・ Erasure of trouble code

AUTOMATIC TRANSMISSION (AW30-40LE) 7A-9

Driving mode select control

・ The TCM selects a suitable driving mode at high A/T oil

temperature (D range).

i)Economy mode ii)Power mode iii)Winter mode (UBS)
iv)HOT1 mode (more than 160℃ TF) v)HOT2 mode (more
than 140℃) vi)L4 mode

・ The priority of driving mode:

Economy < Power < L4 < Winter < HOT1 < HOT2

Oil temperature warning function

・ If the transmission oil temperature sensor senses that

transmission oil temperature is greater than 146℃, the TCM turn
on A/T OIL TEMP warning lamp. (The warning lamp is turned off,
if oil temperature is less than 126℃.)

L4 mode control (4×4)

・ The TCM judges whether the transfer is engaged in high or low

based on the ratio rpm data from output speed sensor in the
transmission and the rpm data form speed meter sensor to
select the shift map.

Winter mode control (UBS)

・ The TCM controls the vehicle start smoothly on low frictional road

like snow road by executing this control.

Active condition:

1. Excluding “2”, “L” range
2. Vehicle speed is less than 11 km/h
3. Transmission oil temperature is less than 115℃
4. Throttle opening is less than 8%
5. Excluding winter mode
Cancel condition:
1. When winter mode switch is pushed again
2. When either “2” or “L” is detected
3. Ignition

switch

“OFF”

4. Vehicle speed is more than 34 km/h for 1 second or mode

continuously

5. Transmission oil temperature is more than 130℃

7A-10 AUTOMATIC TRANSMISSION (AW30-40LE)

FAIL-SAFE FUNCITON

Vehicle speed sensor 1, 2

The vehicle speed is detected by two systems, one from a sensor
fitted to the transmission (output shaft revolution sensor) and another
from the speedometer.
In case of malfunction in one of two, the speed signal from the other
is used for control.

Neutral start switch

In case “2” and “L” range signals are on, priority is given “L”.

Shift solenoid S1 and S2

If there is an abnormality is one or both of solenoids, TCM
automatically exerts fail-safe control, thereby maintaining driveability.

Lock-up control solenoid S3

This keeps lock-up control solenoid S3 off.

SHIFT SOLENOID S1, S2 (FAIL-SAFE FUNCTION)

NORMAL

SOLENOID S1

MALFUNCTIONING

SOLENOID S2

MALFUNCTIONING

BOTH SOLENOIDS

MALFUNCTIONING

Solenoid Solenoid Solenoid Solenoid

Range

S1 S2

Gear

position

S1 S2

Gear

position

S1 S2

Gear

position

S1 S2

Gear

position

ON OFF 1st ×

ON←

(OFF)

3rd ON × 1st ×

× OD

ON ON 2nd × ON 3rd

OFF←

(ON)

× OD ×

× OD

OFF ON 3rd × ON 3rd

OFF

× OD ×

× OD

“D” range

OFF OFF OD × OFF OD OFF

× OD ×

× OD

ON OFF 1st ×

ON←

(OFF)

3rd ON × 1st ×

× 3rd

ON ON 2nd × ON 3rd

OFF←

(ON)

× 3rd ×

× 3rd

“2” range

OFF ON 3rd × ON 3rd

OFF

× 3rd ×

× 3rd

ON OFF 1st × OFF 3rd ON × 1st ×

× 3rd

“L” range

ON ON 2nd ×

OFF←

(ON)

3rd ON × 1st ×

× 3rd

( ): Fail-safe function X: Malfunctions

AUTOMATIC TRANSMISSION (AW30-40LE) 7A-11

MAJOR INPUT/OUTPUT COMPONENTS

Component Function

Vehicle speed sensor 1 (Speedometer)

Detects the vehicle speed

Vehicle speed sensor 2 (Transmission)

Detects the vehicle speed

Throttle position sensor

Detects the injection pump lever opening rate

Neutral start switch

Detects the select lever position

Pattern select switch

Detects whether the driver has select “NORMAL” or
“POWER”, or “WINTER” (UBS) mode

A/T Fluid temperature sensor

Detects the A/T Fluid temperature

Overdrive switch

Detects whether the driver has selected O/D

Brake lamp switch

Detects whether the driver has pressed the brake pedal or not

In

pu

t

Diagnostic start switch

Starts self-diagnosis and displays a code for faulty part if any

Inpu

t/

Ou

tp

ut

Diagnosis connector

When connected with Tech 2 or tester, can communicate the
data for function check, etc.

Shift solenoid S1, S2

Selects shift point and gear position suited to the vehicle
running condition on the basis of TCM output.

Lock-up control solenoid S3

Control the lock-up clutch suited to the vehicle running
condition on the basis of TCM output.

“CHECK TRANS” lamp

When trouble has occurred to throttle position sensor, vehicle
speed sensor, or solenoid, “CHECK TRANS” lamp is blinked
to warn the driver. If also displays the trouble code.

“AT OIL TEMP” lamp

When A/T Fluid temperature is high, “AT OIL TEMP” lamp is
on to be warm the driver. (Turned on at greater than 146℃.
Turned off at less than 126℃.)

Power mode lamp

Informs the driver whether the vehicle is in power mode or not.

Outp

ut

Winter mode lamp (UBS)

Informs the driver whether the vehicle is in winter mode or not.

C

om

put

er

Transmission Control Module (TCM)

Based on the signal from each switch and sensors, judges
necessary shift point and lock-up operation, and send signal to
each solenoid.