CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-31

A750E AND A750F AUTOMATIC TRANSMISSIONS

 DESCRIPTION

 The new Hilux has adopted the A750E (for 2WD model) and A750F (for 4WD model) automatic
transmissions on the 1GR-FE engine models. These automatic transmissions are 5-speed Super ECT
(Electronic Controlled Transmission) to improve the vehicle’s fuel economy and driving performance.
 The only difference between the A750E and A750F is in the extension housing and output shaft.
 A low-viscosity type transmission fluid (TOYOTA ATF WS) has been adopted.

271CH26

A750E

271CH27
A750F

Specifications

Transmission Type A750E (2WD) A750F (4WD)

1st 3.520 
2nd 2.042 
3rd 1.400 
Gear Ratio
4th 1.000 
5th 0.716 
Reverse 3.224 
Fluid Capacity Liters (US qts, Imp. qts) 10.9 (11.5, 9.6) 
CH-32 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS
TOYOTA ATF WS
Fluid Type 
or Equivalent
Weight (Reference)* kg (lb) 85.5 (188.5) 86.3 (190.3)

*: Weight shows the figure with the oil fully filled.

 C2 C3
B3 F1 B4B1 F3
B2
CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-33
Input Shaft

Specifications of the clutch, brake and gear train

C1 No.1 Clutch 6
C2 No.2 Clutch 5
C3 No.3 Clutch Rear Planetary 5
B1 No.1 Brake The No. of Discs Gear 3
B2 No.2 Brake 3
B3 No.3 Brake 4
B4 No.4 Brake 8
F1 No.1 One-Way Clutch C1 Center Planetary Gear 18
F2 Front Planetary Gear
F2 No.2 One-Way Clutch The No. of Sprags 25
271CH28

F3 No.3 One-Way Clutch 26

The No. of Sun Gear Teeth 40
Inner 22
Front Planetary Gear The No. of Pinion Gear Teeth
Outer 21
The No. of Ring Gear Teeth 91
The No. of Sun Gear Teeth 31
Center Planetary Gear The No. of Pinion Gear Teeth 23
The No. of Ring Gear Teeth 77
The No. of Sun Gear Teeth 25
Rear Planetary Gear The No. of Pinion Gear Teeth 19
The No. of Ring Gear Teeth 63
CH-34 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

 ATF

1. General

 The TOYOTA ATF WS has been adopted to reduce the resistance of the ATF and improve fuel economy
by reducing its viscosity in the practical operating range. At the high-temperature end, its viscosity is the
same as that of the TOYOTA ATF Type T-IV, which ensures the durability of the automatic transmission.
 There is no interchangeability between the TOYOTA ATF WS and other types of ATFs (TOYOTA ATF
Type T-IV, D-II.)

: TOYOTA ATF Type T-IV

Viscosity : TOYOTA ATF WS
Reduced Viscosity

High

High Temperature 259LSK03

Service Tip
If a vehicle with a transmission filled with TOYOTA ATF WS is replenished with another type of
ATF, the vehicle might not start off at extremely low temperatures. However, it will start off after it
has been warmed up for a few minutes.

2. ATF Filling Procedures

The ATF filling procedure has been changed in order to improve the accuracy of the ATF level when being
repaired or replaced. As a result, the oil filler tube and the oil level gauge used in the conventional
automatic transmission have been discontinued, achieving a maintenance-free ATF level.
Refill Plug
 This mechanism consists of a refill plug, overflow plug, ATF temp. sensor No. 2, and ATF temp.
warning light.

Proper
Level

271CH60
Overflow Plug
CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-35
CH-36 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

Service Tip
ATF Filling procedures using SST (09843-18040)
When a large amount of ATF needs to be filled (i. e. after removal and installation of oil pan or torque
converter), perform the procedure from step 1. When the small amount of ATF is required (i. e. removal
and installation of oil cooler tube, repair of oil leak), perform the procedure from step 7.
1) Raise the vehicle keeping it level.
2) Remove the refill plug and overflow plug.
3) Fill ATF from the refill plug until it overflows from the overflow plug.
 The fluid to fill should be TOYOTA ATF WS.
4) Install the overflow plug.
5) Fill the specified amount of ATF determined by the procedure and install the refill plug.
 Example
Amount
Procedure
Liters (US qts, Imp.qts)
Removal and installation of an oil pan (including oil drainage) 1.7 (1.80, 1.50)
Removal and installation of a transmission valve body 4.3 (4.54, 3.78)
Replacement of a torque converter 5.4 (5.70, 4.75)
6) Lower the vehicle down.
7) Use the SST (09843-18040) to short the terminals TC and CG of the DLC3 connector:
8) Start the engine and allow it to idle.
 A/C switch must be turned off.
9) Move the shift lever slowly through each of the positions from the P to the L position, and move it
back to the P position.
10) Move the shift lever to the D position, and quickly move then back and forth between N and D (once
per less than 1.5 seconds) for at least six seconds. This will activate the oil temperature detection mode.
Standard: The ATF temp. warning light remains illuminated for 2 seconds and it goes off.
11) Return the shift lever to the P position and disconnect the terminal TC.
12) Idle the engine to raise the oil temperature.
13) Immediately after the ATF temp. warning light turns on, lift the vehicle up.
 The ATF temp. warning light will indicate the ATF temp. according to the following table. (Insert
table here)
Less than optimized More than optimized
ATF Temp. Optimized temperature
temperature temperature

A/T OIL TEMP

Turn OFF Turn ON Blinking
warning light

14) Remove the overflow plug and adjust oil quantity.

 If the ATF overflows, go to step 17, and if the ATF does not overflow, go to step 15.
15) Remove the refill plug.
16) Fill ATF to the refill plug until it flows out from the overflow plug.
17) When the ATF flow slows to a trickle, install the overflow plug through the new gasket.
18) Install the refill plug (only if the refill plug has been removed).
19) Lower the vehicle down.
20) Turn the ignition switch OFF to stop the engine.
For details about the ATF Filling procedures, see the Hilux Repair Manual.
 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-37

 TORQUE CONVERTER

 A compact, lightweight and high-capacity torque converter has been adopted.

 The torque converter clutch supports lock-up clutch control, thus improving the fuel economy.

Specifications
Turbine Runner

3-Element, 1-Step, 2-Phase

Type
(with lock up mechanism) Pump Impeller
Lock-up
Stall Torque Ratio 1.85 Clutch Stator
One-way Clutch

229LC172

 OIL PUMP

The oil pump is coupled with the torque converter. It lubricates the planetary gear units and supplies
operating pressure for hydraulic control.
The material of the pump cover is aluminum to reduce weight.

Pump Cover

Driven Gear
Pump Body
Drive Gear

Stator Shaft
CH-38 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS
232CH89
 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-39

 PLANETARY GEAR UNIT

1. Construction

 The 5-speed configuration has been achieved using 3 (front, center, and rear) planetary gears, thus
creating a 5-speed automatic transmission.
 The front planetary carrier, made of aluminum, has been adopted to reduce the weight.
 A centrifugal fluid pressure canceling mechanism has been adopted in the C 1, C2, and C3 clutches that are
applied when shifting from 2nd to 3rd, from 3rd to 4th and from 4th to 5th. For details, refer to page CH-
10.

B3 B1 B2 B4

F2 F1 Front Planetary F3
Gear
C3

Input Shaft C1

Sun Gear Output Shaft

C2
Intermediate Shaft
Rear Planetary Gear
Center Planetary Gear 229LC160

2. Function of Component

Component Function

C1 No.1 Clutch Connects input shaft and intermediate shaft.

C2 No.2 Clutch Connects input shaft and center planetary carrier.
C3 No.3 Clutch Connects input shaft and front sun gear.
Prevents front planetary carrier from turning either clockwise or
B1 No.1 Brake
counterclockwise.
Prevents front and center ring gear from turning either clockwise or
B2 No.2 Brake
counterclockwise.
Prevents outer race of F 2 from turning either clockwise or
B3 No.3 Brake
counterclockwise.
Prevents rear ring gear from turning either clockwise or
B4 No.4 Brake
counterclockwise.
F1 No.1 One-Way Clutch Prevents front planetary carrier from turning counterclockwise.
When B3 is operating, prevents planetary sun gear from turning
F2 No.2 One-Way Clutch
counterclockwise.
CH-40 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS
Prevents center planetary carrier and rear ring gear from turning
F3 No.3 One-Way Clutch
counterclockwise.
These gears change the route through which driving force is
Planetary Gears transmitted, in accordance with the operation of each clutch and brake,
in order to increase or reduce the input and output speed.
 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-41

3. Transmission Power Flow

Shift One-way
Solenoid Valve Clutch Brake
Lever Gear Clutch
Position S1 S2 SR SL1 SL2 SLU C1 C2 C3 B1 B2 B3 B4 F1 F2 F3
P Park ON ON
R Reverse* ON ON    
N Neutral ON ON
1st ON ON  
2nd ON ON ON    
D 3rd ON ON    
4th ON    
5th ON ON ON    
1st ON ON  
2nd ON ON ON    
4
3rd ON ON    
4th ON ON    
1st ON ON  
3 2nd ON ON ON    
3rd* ON    
1st ON ON  
2
2nd* ON ON ON   
L 1st* ON  

: Operation
: Operate but is not related to power transmission
* : with engine brake
CH-42 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

1st Gear (D Position)

B3 B1 B2 B4

F2 F1 Front Planetary F3
Gear
C3

C1

Input Shaft
Sun Gear Output Shaft

C2 Intermediate Shaft

Rear Planetary Gear

Center Planetary Gear

229LC174

2nd Gear (D Position)

B3 B1 B2 B4

F2 F1 Front Planetary F3
Gear
C3

C1

Input Shaft Output Shaft

Sun Gear
C2 Intermediate Shaft
Rear Planetary Gear

Center Planetary Gear 232CH157

 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-43

3rd Gear (D Position)

B3 B1 B2 B4

F2 F1 Front Planetary F3
Gear
C3

C1

Input Shaft Output Shaft

Sun Gear

C2 Intermediate Shaft
Rear Planetary Gear

Center Planetary Gear 229LC176

CH-44 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

4th Gear (D Position)

B3 B1 B2 B4

F2 F1 Front Planetary F3
Gear
C3

C1

Input Shaft Output Shaft

Sun Gear
C2 Intermediate Shaft
Rear Planetary Gear
Center Planetary Gear 229LC177

5th Gear (D Position)

B3 B1 B2 B4

F2 F1 Front Planetary F3
Gear
C3

C1

Input Shaft Output Shaft

Sun Gear
C2 Intermediate Shaft
Rear Planetary Gear
Center Planetary Gear 229LC178
 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-45

1st Gear (L Position)

B3 B1 B2 B4

F2 F1 Front Planetary F3
Gear
C3

C1

Input Shaft Output Shaft

Sun Gear
C2 Intermediate Shaft
Rear Planetary Gear
Center Planetary Gear 232CH118
CH-46 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

2nd Gear (2nd Position)

B3 B1 B2 B4

F2 F1 Front Planetary F3
Gear
C3

C1

Input Shaft Output Shaft

Sun Gear
C2 Intermediate Shaft
Rear Planetary Gear
Center Planetary Gear 232CH119

3rd Gear (3rd Position)

B3 B1 B2 B4

F2 F1 Front Planetary F3
Gear
C3

C1

Input Shaft Output Shaft

Sun Gear
C2 Intermediate Shaft
Rear Planetary Gear
Center Planetary Gear 232CH120

Reverse Gear (R Position)

B3 B1 B2 B4

F2 F1 Front Planetary F3
Gear

C3

C1
 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-47

Input Shaft Output Shaft

Sun Gear

C2 Intermediate Shaft

Rear Planetary Gear

Center Planetary Gear 232CH158

CH-48 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

4. Centrifugal Fluid Pressure Canceling Mechanism

There are two reasons for improving the conventional clutch mechanism:
 To prevent the generation of pressure by centrifugal force applied to the fluid in the piston fluid pressure
chamber (hereafter referred to as “chamber A”) when the clutch is released, a check ball is provided.
Therefore, before the clutch could be subsequently applied, it took time to fill chamber A.
 During shifting, in addition to the original clutch pressure that is controlled by the valve body,
centrifugal pressure acts on the fluid in the chamber A exerting increased pressure depending upon
revolution fluctuations.
To address these two needs for improvement, a canceling fluid pressure chamber (hereafter referred to as
"chamber B") has been provided opposite chamber A.

Piston C1 Clutch

Chamber A Chamber B

271CH40

By utilizing the lubrication fluid such as that of the shaft, the same amount of centrifugal force is applied,
thus canceling the centrifugal force that is applied to the piston itself. Accordingly, it is not necessary to
discharge the fluid through the use of a check ball, and a highly responsive and smooth shifting
characteristic has been achieved.

Centrifugal Fluid Pressure Clutch

Applied to the Chamber A
Target Fluid Pressure

Centrifugal Fluid Pressure

Applied to Chamber B
Piston Fluid
Pressure Chamber B
Chamber (Lubrication Fluid)

Fluid Pressure
Applied to Piston Shaft Side
157CH17

Fluid pressure  Centrifugal fluid pressure Target fluid pressure

=
applied to piston applied to chamber B (original clutch pressure)
CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-49
CH-50 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

 VALVE BODY UNIT

1. General

The valve body unit consists of the upper (No.1 and No.2) and lower valve bodies and 7 solenoid valves.

Solenoid Valve SR
Solenoid Valve SLU
Solenoid Valve SL2
No.2 Upper Valve Body

No.1 Upper Valve Body

Solenoid Valve S2
Solenoid Valve S1
Lower Valve Body

Solenoid Valve SL1

Solenoid Valve SLT
229LC161

No.1 Upper Valve Body

Solenoid Modulator Valve

2 – 3 Shift Valve
B1 Accumulator Clutch Lock Valve
1 – 2 Shift Valve
B1 Apply Control Valve

Secondary Regulator Valve Brake Control Valve

3 – 4 Shift Valve
Lock-up Relay Valve
229LC162
C3 Check Valve
Lock-up Control Valve
CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-51
CH-52 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

No.2 Upper Valve Body

Coast Brake Relay Valve

229LC163

Lower Valve Body

Clutch Apply Control Valve

Sequence Valve

SLT Damper

Clutch Control Valve

229LC164
Primary Regulator Valve Accumulator Control Valve
 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-53

2. Solenoid Valve

Solenoid Valve S1, S2 and SR

 Solenoid valves S1 and SR use a 3-way solenoid valve.

 Solenoid valve S2 uses a 2-way solenoid valve.
 A filter has been provided at the tip of the solenoid valve to further improve operational reliability.

Filter Drain

Line
Pressure

Control Pressure Control Pressure

Solenoid Valve S1 OFF Solenoid Valve S1 ON

229LC165

Control Pressure

Line
Filter
Pressure

Solenoid Valve S2 OFF Solenoid Valve S2 ON

229LC166

Function of Solenoid Valve S1, S2 and SR

Solenoid Valve Type Function

S1 3-way Switches the 2 - 3 shift valve
 Switches the 1 - 2 shift valve
S2 2-way
 Switches the 3 - 4 shift valve
SR 3-way Switches the clutch apply control valve
CH-54 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

Solenoid Valve SL1, SL2, SLT and SLU

 In order to provide a hydraulic pressure that is proportion to current that flows to the solenoid coil, the
solenoid valve SL1, SL2, SLT, and SLU linearly control the line pressure and clutch and brake
engagement pressure based on the signals it receives from the Engine & ECT ECU.
 The solenoid valves SL1, SL2, SLT, and SLU have the same basic structure.

Spool Valve Solenoid Coil

Sleeve

Solenoid Valve SLT

Hydraulic Hydraulic
Pressure Pressure

Current Current

Solenoid Valve SL1, SL2, and SLT Solenoid Valve SLU

229LC181

Function of Solenoid Valve SL1, SL2, SLT and SLU

Solenoid Valve Function

 C1 clutch pressure control
SL1
 Accumulator back pressure control
SL2 B1, B2 and B4 brake pressure control
 Line pressure control
SLT
 Accumulator back pressure control
 Lock-up clutch pressure control
SLU
 Accumulator back pressure control
CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-55
CH-56 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

 ELECTRONIC CONTROL SYSTEM

1. General

The electronic control system of the A750E and A750F automatic transmissions consist of the control
listed below.

System Function
 Controls the pressure that is applied directly to B 1 brake and C1 clutch
by actuating the linear solenoid valves SL1 and SL2 in accordance with
Clutch Pressure Control
the Engine & ECT ECU signals.
(See Page XX)
 The solenoid valve SLT and SL1 minutely controls the clutch pressure
in accordance with the engine output and driving conditions.
Actuates the solenoid valve SLT to control the line pressure in accordance
Line Pressure Control
with information from the Engine & ECT ECU and the operating
(See Page XX)
conditions of the transmission.
Retards the engine ignition timing temporarily to improve shift feeling
Engine Torque Control
during up or down shifting.
The Engine & ECT ECU sends current to the solenoid valve S1, S2 and/or
Shift Timing Control
SR based on signals from each sensor and shifts the gear.
The Engine & ECT ECU sends current to the shift solenoid valve SLU
Lock-up Timing Control based on signals from each sensor and engages or disengages the lock-up
clutch.
When the shift lever is shifted from “N” to “D” position, the gear is
“N” to “D” Squat Control
temporarily shifted to 2nd and then to 1st to reduce vehicle squat.
Based on the signals from various sensors, the Engine & ECT ECU
AI (Artificial Intelligence)
determines the road conditions and the intention of the driver. Thus, the
-SHIFT
shift pattern is automatically regulated to an optimal level, thus improving
(See Page XX)
drivability.
When the Engine & ECT ECU detects a malfunction, the Engine & ECT
ECU makes a diagnosis and memorizes the failed section.
Diagnosis
All the DTC (Diagnostic Trouble Code) have been made correspond to the
SAE controlled codes.
Even if a malfunction is detected in the sensors or solenoids, the Engine &
Fail-safe ECT ECU effects fail-safe control to prevent the vehicle’s drivability from
being affected significantly.
 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-57

2. Construction

The configuration of the electronic control system in the new Hilux’s A750E and A750F is as shown in the
following chart.
VG S1
AIR FLOW METER SOLENOID VALVE S1

CRANKSHAFT POSITION NE
SENSOR
S2
SOLENOID VALVE S2
VTA1
THROTTLE POSITION SENSOR
VTA2

ACCELERATION PEDAL VPA

SL1
POSITION SENSOR VPA2 SOLENOID VALVE SL1

THW
WATER TEMP. 　 SENSOR

SL2
NSW
NEUTRAL START SWITCH SOLENOID VALVE SL2
P, R, D, 3, 2

SHIFT LOCK ECU

SLT
SOLENOID VALVE SLT
TRANSMISSION CONTROL 4, L
SWITCH

SLU
VEHICLE SPEED SENSOR SOLENOID VAVLE SLU
Engine &
ECT ECU
SPD
COMBINATION METER
SR
SOLENOID VALVE SR
NT
INPUT SPEED SENSOR

SP2
IGT1~IGT6
OUTPUT SPEED SENSOR IGNITION COIL with IGNITER
IGF

THO1
ATF TEMP. SENSOR NO.1

THO2
ATF TEMP. SENSOR NO.2 COMBINATION METER
OILW
STP ATF TEMP. WARNING LIGHT*
STOP LIGHT SWITCH ST1-
W CHECK ENGINE WARNING
2
1 4WD* LIGHT
4WD CONTROL ECU*

3
1
4WD*
4WD DETECTION SWITCH*
TC

L4 SIL
L4 POSITION SWITCH*1 DLC3
WFSE

271CH29
*1: A750F AT Models
*2: With A.D.D.Shift Actuator
*3: Without A.D.D. Shift Actuator
CH-58 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

3. Layout of Main Components

Check Engine
Warning Light

ATF Temp.
Warning Light
Engine & Stop Light
ECT ECU Switch

DLC3

Shift Lock ECU

 Transmission
Shift Solenoid Valve S2 Control Switch
Shift Solenoid Valve S1
Shift Solenoid Valve
SL1
Shift Solenoid
Valve SLT

Shift Solenoid
Valve SR

Shift Solenoid
Valve SLU Neutral Start
Switch
Shift Solenoid Valve SL2 Output Speed Sensor
ATF Temp. Sensor No.2
Input Speed Sensor
ATF Temp. Sensor No.1
271CH30
 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-59

4. Construction and Operation of Main Components

ATF Temp. Sensor No.1 and No.2

 ATF temp. sensor No.1 (THO1) is used for hydraulic pressure control. This sensor is used for revision
of clutches and brakes pressure to keep smooth shift quality every time.
 ATF temp. sensor No.2 (THO2) is used for shifting of the shift timing control of ECT when the ATF
temp. is high. However, on the 4WD model, it is also used for the ATF temp. warning light.

ATF Temperature Sensor No.1 (THO1)

Front

229LC132
ATF Temperature Sensor No.2 (THO2)

Transmission Control Switch and Park/Neutral Position Switch

The Engine & ECT ECU uses these switches to detect the shift position.
 The neutral start switch sends the P, R, N, D, 3, 2, and NSW position signals to the Engine & ECT
ECU. It also sends signals for the shift indicator light (P, R, N, and 3rd) in the combination meter (only
for optitron type).
 The transmission control switch is located in the shift lock ECU. This switch sends the 4th and L
signals to the Engine & ECT ECU. It also sends signals for the shift position indicator light (D, 4th,
Engine & ECT ECU
2nd, and L)Neutral Start
in the combination meter.
Switch P R N D 2
NSW 4 3 L
To Starter
Wiring Diagram NSW Shift Lock ECU
Relay
P
Transmission
R Control Switch
N
+B D NSSD
3 AT4
2
ATD

NSSL
ATL

AT2

P R N D 4 3 2 L

Combination Meter
(Only for Optitron Type)
232CH92
CH-60 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS
 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-61

Input Speed Sensor and Output Speed Sensor

The A750E and A750F automatic transmissions use an input speed sensor (for NT signal) and output
speed sensor (for SP2 signal). Thus, the Engine & ECT ECU can detect the timing of the shifting of the
gears and appropriately control the engine torque and hydraulic pressure in response to the various
conditions.
These speed sensors are the pick-up coil type.
 The input speed sensor detects the input speed of the transmission. The clutch drum is used as the
timing rotor for this sensor.
 The output speed sensor detects the speed of the output shaft. The parking gear on the rear planetary
gear is used as the timing rotor for this sensor.

Clutch Drum Output Speed Sensor

(Timing Rotor)

Parking Gear
(Timing Rotor)
Input Speed Sensor
232CH91
CH-62 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

5. Clutch Pressure Control

Clutch to Clutch Pressure Control

This control is used for shifting from the 4th to 5th gear and from the 5th to 4th gear.
Actuates solenoid valves SL1 and SL2 in accordance with the signals from the Engine & ECT ECU, and
guides this output pressure directly to the control valves B 1 and C1 in order to regulate the line pressure
that acts on the B1 brake and C1 clutch.
As a result, high response and excellent shift characteristics have been realized.

Engine &
ECT ECU  Input Speed Sensor
SL1 SL2  Output Speed Sensor
 Throttle Position Sensor
 Air Flow Meter
 ATF Temp. Sensor No.1
C1 Control Valve B1 Control Valve  Water Temp. Sensor
 Accelerator Pedal Position
Sensor
C1 B1
C1 B1
4th  5th OFF ON
5th  4th ON OFF
Line Pressure
232CH141

Clutch Pressure Optimal Control

The Engine & ECT ECU monitors the signals from various types of sensor such as the input speed
sensor, allowing shift solenoid valves SLT and SL1 to minutely control the clutch pressure in accordance
with engine output and driving conditions.
As a result, smooth shift characteristics have been realized.

Target rpm
Change Ratio Engine & ECT ECU
Input
Shaft Transmission
rpm CPU
Engine CPU

Practical rpm Change Ratio

Time

Input Speed Output Speed

Sensor Sensor

ATF Temp.
Sensor No.1
CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-63

Accumulator
Clutch Control Valve
Brake Output
Solenoid Valve Shaft
Pressure
SL1, SLT Torque

Solenoid Drive Signal Time 232CH140

CH-64 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

6. Line Pressure Optimal Control

Through the use of the solenoid valve SLT, the line pressure is optimally controlled in accordance with the
engine torque information, as well as with the internal operating conditions of the toque converter and the
transmission.
Accordingly, the line pressure can be controlled minutely in accordance with the engine output, traveling
condition, and the ATF temp., thus realizing smooth shift characteristics and optimizing the workload in
the oil pump.

Engine & ECT ECU

Line Pressure Throttle Valve Opening
Engine Intake Air Volume
CPU
Water Temp.
Engine rpm

Primary Regulator
Input Speed Sensor
Transmission
CPU ATF Temp.
Shift Position

Solenoid Drive
Signal
Fluid
Pressure

Current

Pump Throttle Pressure

Solenoid Valve SLT

232CH150
 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-65

7. AI (Artificial Intelligence)- SHIFT Control

General

In addition to the switching of the shift pattern through the pattern select switch, the AI- SHIFT control
enables the Engine & ECT ECU to estimate the road conditions and the driver's intention in order to
automatically switch the optimal shift pattern. As a result, a comfortable ride has been achieved.

Basic Shift
Pattern Control
 Throttle Opening
AI-SHIFT
Angle

 Vehicle Speed Road Condition

 Engine Speed Uphill/ Downhill Driving

Estimating the Grade
 Brake Signal

 Vehicle Acceleration Road Condition

Small Large Support Control
: Criterion Acceleration

: Actual Acceleration



Driver’s Intention

 Acceleration Driver’s Intention

Pedal Operation Estimating the
Support Control
 Vehicle Condition Driver’s Intention

232CH143
CH-66 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

Road Condition Support Control

Under Road Condition Support Control, the Engine & ECT ECU identifies throttle valve opening angle
and the vehicle speed whether the vehicle is being driven uphill or downhill.
To achieve an optimal drive force while driving uphill, this control prevents the transmission from
upshifting to the 4th or 5th gear. To achieve an optimal engine brake effect while driving downhill, this
control automatically downshifts the transmission to the 4th or 3rd gear.

5th
5th 4th 5th 3rd 5th 4th (Brake Operating) without Control

with Control
5th 4th 3rd 4th 3rd 4th 5th

229LC183

Driver's Intention Support Control

Estimates the driver's intention based on the accelerator operation and vehicle condition to switch to a
shift pattern that is well-suited to each driver, without the need to operate the shift pattern select switch.
 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-67

8. Diagnosis

 When the Engine & ECT ECU detected a malfunction, the Engine & ECT ECU makes a diagnosis and
memorizes the failed section. Furthermore, the check engine warning light in the combination meter
illuminates or blinks to inform the driver.
 At the same time, the DTCs (Diagnosis Trouble Codes) are stored in memory. The DTCs can be read by
connecting a intelligent tester-II to DLC3.
For details, see the Hilux Repair Manual.

9. Fail Safe

This function minimizes the loss of operability when any abnormality occurs in each sensor or solenoid.

Fail-Safe Control List

Malfunction Part Function

During an output speed sensor malfunction, shift control is effected
Output Speed Sensor (SP2)
through the input speed sensor signal (SPD).
During an ATF temp. sensor No.1 malfunction, 5th up-shift and lock-up
ATF Temp. Sensor No.1
clutch control are prohibited.
The current to the failed solenoid valve is cut off and control is effected
Solenoid Valve by operating the other solenoid valves with normal operation.
S1, S2 and SR Shift control is effected depending on the failed solenoid as described in
the table on the next page.
Solenoid Valve During a solenoid valve SL1 or SL2 malfunction, 5th up-shift is
SL1 and SL2 prohibited.
During a solenoid valve SLU malfunction, the current to the solenoid
Solenoid Valve SLU valve is stopped. Because this stops lock-up control and lock-up control,
and fuel economy decreases.
During a solenoid valve SLT malfunction, the current to the solenoid
valve is stopped. Because this stops line pressure optimal control, the
Solenoid Valve SLT
shift shock increases. However, shifting is effected through normal clutch
pressure control.
CH-68 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

Normal Shift Solenoid Valve S1 Malfunction

Position Shift Solenoid Shift Solenoid
Gear Gear
S1 S2 SR SL1 SL2 S1 S2 SR SL1 SL2
OFF 4th
ON OFF OFF OFF ON 1st  OFF OFF ON
 ON  3rd
ON ON OFF OFF ON 2nd  ON OFF OFF ON 3rd
D
OFF ON OFF OFF ON 3rd  ON OFF OFF ON 3rd
OFF OFF OFF OFF ON 4th  OFF OFF OFF ON 4th
OFF OFF ON ON OFF 5th  OFF ON ON OFF 5th

OFF 4th
ON OFF OFF OFF ON 1st  OFF OFF ON
 ON  3rd

4 ON ON OFF OFF ON 2nd  ON OFF OFF ON 3rd

OFF ON OFF OFF ON 3rd  ON OFF OFF ON 3rd
OFF OFF OFF OFF ON 4th  OFF OFF OFF ON 4th
OFF ON  3rd 
ON OFF OFF OFF ON 1st  OFF OFF
 ON OFF 3rd (E/B)
ON  3rd 
3 ON ON OFF OFF ON 2nd  ON OFF OFF
OFF 3rd (E/B)

OFF ON OFF OFF OFF 3rd (E/B)  ON OFF OFF OFF 3rd (E/B)

ON OFF OFF OFF ON 1st  OFF OFF OFF ON 1st

2
ON ON ON OFF OFF 2nd (E/B)  ON ON OFF OFF 3rd (E/B)

L ON OFF OFF OFF OFF 1st (E/B)  OFF OFF OFF OFF 1st (E/B)

Shift Solenoid Valve S2 Malfunction Shift Solenoid Valve SR Malfunction

Position Shift Solenoid Shift Solenoid

Gear Gear
S1 S2 SR SL1 SL2 S1 S2 SR SL1 SL2
ON  OFF OFF ON 1st ON OFF  OFF ON 1st
ON  1st 
 OFF OFF ON ON ON  OFF ON 2nd
OFF 4th
D OFF  OFF OFF ON 4th OFF ON  OFF ON 3rd
OFF  OFF OFF ON 4th OFF OFF  OFF ON 4th
OFF  ON ON OFF 5th OFF OFF  ON OFF 4th
ON  OFF OFF ON 1st ON OFF  OFF ON 1st
ON  1st 
 OFF OFF ON ON ON  OFF ON 2nd
4 OFF 4th
OFF  OFF OFF ON 4th OFF ON  OFF ON 3rd
OFF  OFF OFF ON 4th OFF OFF  OFF ON 4th
ON  OFF OFF ON 1st ON OFF  OFF ON 1st
ON  ON  1st 
 OFF OFF ON ON  OFF ON 2nd
3 OFF OFF 3rd (E/B)
OFF 3rd (E/B)
OFF  OFF OFF OFF 3rd (E/B) OFF ON  OFF
 ON  3rd
ON  OFF OFF ON 1st ON OFF  OFF ON 1st
2 ON  OFF 2nd (E/B)
 ON OFF ON ON  OFF OFF 2nd
OFF  ON  4th
L ON  OFF OFF OFF 1st (E/B) ON OFF  OFF OFF 1st (E/B)

E/B: Engine Brake

 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS CH-69

Shift Solenoid Valve S1 and S2 Malfunction Shift Solenoid Valve S1 and SR Malfunction
Position Shift Solenoid Shift Solenoid
Gear Gear
S1 S2 SR SL1 SL2 S1 S2 SR SL1 SL2
OFF 4th
  OFF OFF ON 4th   OFF ON
 ON  3rd

  OFF OFF ON 4th  ON  OFF ON 3rd

D   OFF OFF ON 4th  ON  OFF ON 3rd
  OFF OFF ON 4th  OFF  OFF ON 4th
ON  OFF
  ON ON OFF 5th  OFF  4th
OFF  ON
OFF 4th
  OFF OFF ON 4th   OFF ON
 ON  3rd

4   OFF OFF ON 4th  ON  OFF ON 3rd

  OFF OFF ON 4th  ON  OFF ON 3rd
  OFF OFF ON 4th  OFF  OFF ON 4th
ON  3rd  OFF
  OFF OFF   OFF ON 3rd
OFF 3rd (E/B)  ON
ON  3rd 
3   OFF OFF
OFF 3rd (E/B)
 ON  OFF ON 3rd

OFF 3rd (E/B)

  OFF OFF OFF 3rd (E/B)  ON  OFF
 ON  3rd
  OFF OFF ON 1st  OFF  OFF ON 1st
2 OFF
  ON OFF 4th  ON  OFF OFF 2nd
ON
L   OFF OFF OFF 1st (E/B)  OFF  OFF OFF 1st (E/B)

Shift Solenoid Valve S2 and SR Malfunction Shift Solenoid Valve S1,S2 and SR Malfunction

Position Shift Solenoid Shift Solenoid

Gear Gear
S1 S2 SR SL1 SL2 S1 S2 SR SL1 SL2
ON   OFF ON 1st    OFF ON 4th
ON  1st 
  OFF ON    OFF ON 4th
OFF 4th
D OFF   OFF ON 4th    OFF ON 4th
OFF   OFF ON 4th    OFF ON 4th
ON  OFF ON  OFF 
OFF   4th    4th
OFF  ON OFF ON
ON   OFF ON 1st    OFF ON 4th
ON  1st 
  OFF ON    OFF ON 4th
4 OFF 4th
OFF   OFF ON 4th    OFF ON 4th
OFF   OFF ON 4th    OFF ON 4th
ON   OFF ON 1st    OFF ON 3rd
ON  1st 
  OFF ON    OFF ON 3rd
3 OFF 3rd
OFF 3rd (E/B) OFF  3rd (E/B)
OFF   OFF    OFF
 ON  3rd ON  3rd
ON   OFF ON 1st    OFF ON 1st
2 OFF 1st (E/B) OFF  1st (E/B)
ON   OFF    OFF
 ON  1st ON  1st
L ON   OFF OFF 1st (E/B)    OFF OFF 1st (E/B)

E/B: Engine Brake

CH-70 CHASSIS ― A750E AND A750F AUTOMATIC TRANSMISSIONS

 SHIFT CONTROL MECHANISM

A gate type shift lever is used in conjunction with the installation of the 5-speed automatic transmission.
With the gate type, the shift lever button and the overdrive switch of the straight type shift lever have been
discontinued. Similar functions are achieved through a single-shift operation (fore-aft and side-to-side).
For details, refer to A340E, A340F, A343E and A343F automatic transmissions on page xx.

Shift Pattern

Shift Lock ECU

Shift Lever Assembly 271CH31