Isuzu KB P190. Service manual - part 1060

CONSTRUCTION AND FUNCTION  7A1-1 

 

SECTION 7A1 

CONSTRUCTION AND FUNCTION (JR405E) 

TABLE OF CONTENTS 

 

PAGE 

Description ......................................................................................................................7A1- 3 

Construction ...............................................................................................................7A1- 3 

Main Data and Specification  .....................................................................................7A1-  4 

Number Plate Location  ..............................................................................................7A1-  5 

Electronic Control Components Location  ...............................................................7A1-  6 

Transmission Control Module (TCM) Peripheral Circuit  .........................................7A1-  7 

Structure and Function of Component  .........................................................................7A1-  8 

Torque Converter (with Lock-up Function)  .............................................................7A1-  8 

Oil Pump  .....................................................................................................................7A1- 9 

Input Shaft  ..................................................................................................................7A1- 10 

Output Shaft  ...............................................................................................................7A1- 10 

Gear Shifting Mechanism  ..........................................................................................7A1- 10 

Control Valve  ..............................................................................................................7A1- 14 

Oil Passage  .................................................................................................................7A1- 19 

Parking Function  ........................................................................................................7A1- 20 

Inhibitor Switch  ..........................................................................................................7A1- 21 

Turbine Sensor  ...........................................................................................................7A1- 22 

Speed Sensor  .............................................................................................................7A1- 22 

Accelerator Pedal Position Sensor  ..........................................................................7A1- 23 

Engine Speed Sensor (=CKP Sensor)  ......................................................................7A1- 23 

Brake Switch  ..............................................................................................................7A1- 24 

Mode Select Switch  ...................................................................................................7A1- 24 

Transmission Control Module (TCM)  .......................................................................7A1- 25 

Control Mechanism  ........................................................................................................7A1- 26 

Content of Function and Control  ..............................................................................7A1- 26 

Control Item, Input and Output  .................................................................................7A1- 29 

Line Pressure Control  ................................................................................................7A1- 30 

Lock-up Control  .........................................................................................................7A1- 30 

Direct Electric Shift Control (DESC)  .........................................................................7A1- 31 

7A1-2  CONSTRUCTION AND FUNCTION 

 

PAGE 

Learning Function  ......................................................................................................7A1- 33 

Major Input/Output Component and Their Functions  .............................................7A1- 34 

Control Circuit Block Diagram  ..................................................................................7A1- 35 

Gear Train (Transmission Mechanism) Operation and Hydraulic Circuit  ..................7A1- 36 

Construction and Operation  .....................................................................................7A1- 36 

Component Name and Function  ...............................................................................7A1- 36 

Component and Their Operating Condition  ............................................................7A1- 37 

 

CONSTRUCTION AND FUNCTION  7A1-3 

 

DESCRIPTION 

CONSTRUCTION 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

1 

Converter Housing 

6  Low Clutch 

11  Oil Pump 

2 

Torque Converter 

7  Low & Reverse Brake 

12  Control Valve 

3 

High Clutch 

8  Output Shaft 

13  Low One-way Clutch 

4 

Reverse Clutch 

9  Extension Housing 

14  Parking Gear 

5 

2-4 Brake 

10  Input Shaft 

 

Figure 1. Construction of Automatic Transmission 

 
The JR405E automatic transmission is electrically controlled by a microcomputer transmission control module 
(TCM). There are four forward speeds and one reverse speed. 
This JR405E automatic transmission employs a clutch pressure direct control system (Direct Electronic Shift 
Control: DESC) using duty cycle type solenoids, which ensure high shift quality. 
This transmission also has a learning function and constantly checks the time of each clutch and brake 
required for the shift in order to match this time with the target value for the optimum shift. 
 
The TCM will automatically select the most appropriate shift points and lock-up points depending on the 
Accelerator pedal opening, the vehicle speed and the vehicle load. 
If any trouble arises in the speed sensor, APP sensor, solenoid, etc., the fail-safe control function is activated 
to keep the running performance. 
Problems with the sensors or the solenoids can quickly be detected with the self diagnosis procedure 
described in this manual. 
 
The JR405E automatic transmission consists of the torque converter, oil pump, input shaft, out put shaft, 
planetary gears and control valves. 
The gear train consists of two planetary gear sets and three multiple plate clutches in combination with two 
multiple plate brakes and a one-way clutch. 

2WD 

4WD

7A1-4  CONSTRUCTION AND FUNCTION 

MAIN DATA AND SPECIFICATION

 

Model 

JR405E 

Torque Converter Type 

Three-Elements, One-Stage & Two-Phases 

Type With Lock-up Function 

Torque Converter Stall Torque Ratio 

1.8 

Name  

ATF DEXRON III 

Quantity 

L (US gal/Imp gal) 

9.2-9.6 (2.43-2.54/2.02-2.11) 

ATF 

Cooling System 

Water Cooled Type (Radiator) 

1st 2.785 

2nd 1.545 

3rd 1.000 

4th (Over Drive) 

0.694 

Gear Ratio 

Reverse 2.272 

Low Clutch 

L/C 

7

High Clutch 

H/C 

5

Reverse Clutch 

R/C 

2

Number of Discs 

Clutch 

Low One-way Clutch 

L/O.C 

1

Set 

Low & Reverse 
Brake 

L&R/B 6

Brake 

2-4 Brake 

2-4/B 

5

Number of Discs 

Sun Gear 

33

Pinion 
Gear 

21

Front Planetary 

Ring Gear 

75

Sun Gear 

42

Pinion 
Gear 

17

Planetary Gear Unit 

Rear Planetary 

Ring Gear 

75

Number of Teeth