Page 1689 of 2100

7A1±2
TRANSMISSION CONTROL SYSTEM (4L30±E)
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 4L30±E is a 4±speed fully automatic transmission. It
uses a microcomputer as a control unit to judge running
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 shift mode select function can
select three shift modes according to the driver's
preference:
Normal mode ±Normal shift pattern.
Winter mode ±Starts in 3rd gear to reduce slippage on
ice or snow.
Power mode has a delayed upshift when more
powerful acceleration is required.
Also, the built±in fail safe function (ªbackup modeº)
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 4L30±E are as follows:
A compact structure consisting of 2 sets of planetary
gears and flat torque converter.
Electronic control selects the optimum shift 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.
Two sets of planetary gears reduce friction of power
train.
Also, a lockup mechanism in the torque converter
reduces fuel consumption.
Wide gear ratio and high torque rate of torque
converter provide excellent starting performance.
Page 1690 of 2100
TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±3
Electronic Control Diagram
C07R200003
Page 1691 of 2100
7A1±4
TRANSMISSION CONTROL SYSTEM (4L30±E)
Powertrain Control Module (PCM)
C07R200004
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TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±5
Control System Diagram
C07R100005
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7A1±6
TRANSMISSION CONTROL SYSTEM (4L30±E)
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 ªbackupº 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 ªNORMALº
mode only when downhill conditions are recognized.
The shift pattern is identical to ªNORMALº 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 ªNORMALº 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.
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TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±7
Shift Mode Control
F07RX001
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7A1±8
TRANSMISSION CONTROL SYSTEM (4L30±E)
Gear Shift Control
F07RT034
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TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±9
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 ªDº range only.
b. Vehicle speed is 7 mph (11 km/h) or less.
c. Transmission oil temperature is 130C (266F) 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 ª3º, ª2º, or ªLº (winter
drive mode is not canceled by selecting ªNº, ªRº,
or ªPº).
c. Ignition key is turned off.
2. Automatic cancellation
a. When vehicle runs at 21mph (34 km/h) or more
for 1 second or more
b. When transmission oil temperature reaches
130C (266F) 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 ªCHECK TRANSº light flashes to alert the driver, and
the transmission must be manually shifted as follows:
Select lever position
Gear Ratio Selected
D4 (Fourth)
Manual 34 (Fourth)
Manual 23 (Third)
Manual L1 (First)
RReverse
Shifts are firmer to prevent clutch slip and consequent
wear. The fault should be corrected as soon as possible.