Isuzu KB P190. Manual — part 992

7A2-2 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

Service Precaution

WARNING: THIS VEHICLE HAS A SUPPLEMENTAL
RESTRAINT SYSTEM (SRS). REFER TO THE SRS
COMPONENT AND WIRING LOCATION VIEW IN
ORDER TO DETERMINE WHETHER YOU ARE
PERFORMING SERVICE ON OR NEAR THE SRS
COMPONENTS OR THE SRS WIRING. WHEN YOU
ARE PERFORMING SERVICE ON OR NEAR THE
SRS COMPONENTS OR THE SRS WIRING, REFER
TO THE SRS SERVICE INFORMATION. FAILURE TO
FOLLOW WARNINGS COULD RESULT IN
POSSIBLE AIR BAG DEPLOYMENT, PERSONAL
INJURY, OR OTHERWISE UNNEEDED SRS SYSTEM
REPAIRS.

CAUTION: Always use the correct fastener in the
proper location. When you replace a fastener, use
ONLY the exact part number for that application.
ISUZU will call out those fasteners that require a
replacement after removal. ISUZU will also call out
the fasteners that require thread lockers or thread
sealant. UNLESS OTHERWISE SPECIFIED, do not
use supplemental coatings (Paints, greases, or
other corrosion inhibitors) on threaded fasteners or
fastener joint interfaces. Generally, such coatings
adversely affect the fastener torque and the joint
clamping force, and may damage the fastener.
When you install fasteners, use the correct
tightening sequence and specifications. Following
these instructions can help you avoid damage to
parts and systems.

General Description

The AW30-40LE is a 4–speed fully electronically
controlled

automatic transmission. It uses a

microcomputer as a control unit to judge driving
conditions including throttle opening rate and vehicle
speed, then it sets the shifting point in the optimum
timing so that best driving performance can be
achieved.

In addition, the built–in driving mode select function can
select three driving modes according to the driver's
preference:

• Normal mode –Normal shift pattern.

• 3rd Start mode –Starts in 3rd gear to reduce slippage

on mud, ice or snow.

• Power mode –Delays upshift timing when more

powerful acceleration is required.

Also, the built–in fail–safe function (“emergency mode")
assures driving performance even if the vehicle speed
sensor, throttle signal or any solenoid fails.

Further, the self–diagnostic function conducts diagnosis
in a short time when the control system fails, thus
improving serviceability.

The major features of AW30-40LE are as follows:

• A compact structure consisting of 2 sets of planetary

gears and flat torque converter.

• Electronic control selects the optimum driving mode

according to the driving conditions.

• Electronic control maintains the optimum hydraulic

pressure for clutch, band brake as well as
transmission so that shift feeling is improved.

• Wide gear ratio and high torque rate of torque

converter provide excellent starting performance.

• Optimum Lock-up control of each driving mode can

have it both ways driving performance and fuel
economy.

• Excellent shift quality can be achieved by the torque

management control through the CAN
communication with the engine.

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-3

Components Location

RTW77ALF002101

Legend

(8) One-way clutch (No.2) (F-2)

(1) Overdrive direct clutch (C-0)

(9) Shift solenoid (S-1)

(2) Overdrive brake (B-0)

(10) Shift solenoid (S-2)

(3) Direct clutch (C-2)

(11) One-way clutch (No.1) (F-1)

(4) Second coast brake (B-1)

(12) Pressure control solenoid (STH)

(5) Forward clutch (C-1)

(13) Lock-up solenoid (SL)

(6) Second brake (B-2)

(14) Overdrive one-way clutch (F-0)

(7) First and reverse brake (B-3)

7A2-4 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

Operating Condition

RTW77ALF002001

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-5

Electronic Control Diagram

RTW77AXF000201