2004 ISUZU TF SERIES automatic transmission

7D1-36 TRANSFER CONTROL SYSTEM
Restriction on operation (4JA1-LT)
The 4H, neutral and 4L shifting mechanism has no synchronization function. Therefore, if relative rotations in the
mechanism become excessive, shifting exerts adverse influence on the internal mechanism of the transfer. To
avoid such a trouble, vehicle condition is detected to restrict the operation (vehicle speed, and TM position).
Requirement to restrict the speed: Vehicle should be in stop.
Requirements for permission of restriction on engine speed: Engine speed should be decreased.
The engine speed of 3000rpm (V6: 2000rpm) or below is advisable.
Requirements for permission of restriction on T/M position restriction:
should be at the neutral.

These requirements for permission should be all met before the switch is operated. If the requirements are met
after operation, operation is not automatically effected but re-operation is required after permission is given.

Note: Don’t’ accelerate engine speed a the time of this operation.

Step 3-3:
Stop the vehicle. (Close the accelerator and decrease the engine speed to below L4: 3000rpm, V6:
2000rpm.)
(In case of AT): Set the transmission select lever to the N position.
(In case of MT): Set the transmission lever to the neutral position. (Stepping on the clutch is
recommendable.) Push the 4L button.
If shifting operation is not completed (the lamp flashes at 2Hz), perform the step 3-1.

4. Shifting from 4L to 4H
4-1 When 4L indicator continues flashing at 2HZ
When shifting from 4L to 4H, the 4L indicator continues flashing at 2Hz until the shifting in the transfer case is
completed. Phases of engaged splines may deviate and the operation may not completed in some cases.
Shifting is completed by correcting the deviation of the splines.

Step 4-1: (same as step 3-1)
(In case of AT): Set the transmission select lever to the D position.
(In case of MT): Shift the transmission lever to a position allowing running and engage the clutch
gently.

4-2 When the indicator continues flashing at 2Hz for 10 seconds and then keeps on at 4L again (AT
vehicle)
This condition occurs when torsional torque has generated between the transmission and the road surface
(use of the parking position on a slope) and resistance against the separation of the driving force cannot be
fully by the waiting mechanism of the transfer.
Shifting is possible by using the brake also at the neutral position of the transmission

Step 4-2: (Same procedure
as the step 3-2)
Set the transmission select lever to the N position.
(Leaving the brake lever and stepping it again is recommendable.)

4-3 When the 4L indicator flashes at 4HZ
Shifting from 4L to 4H is restricted.
When the vehicle is running, transmission lever is at the running range, and the engine speed is high, the
transfer 4L cannot be shifted to 4H.

TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L) 7A2-1
TRANSMISSION
TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L)
CONTENTS

Service Precaution .................................................
7A2-2
General Description ...............................................
7A2-2
Electronic Control Diagram ...............................
7A2-3
Transmission Control Module (TCM) (1/2) ......
7A2-4
Transmission Control Module (TCM) (2/2) ......
7A2-5
TCM Point Table .................................................
7A2-6
TCM Voltage & Resistance Check Sheet .......
7A2-7
Control System Diagram ....................................
7A2-9
Control and Functions ........................................
7A2-10
Gear Shift Control 3rd start ...............................
7A2-10
Mode Type ...........................................................
7A2-10
Mode Selection ....................................................
7A2-10
Comparison of mode ..........................................
7A2-11
3rd start Mode .....................................................
7A2-11
Backup Mode .......................................................
7A2-11
Functions of Input / Output Components ........
7A2-12
CAN bus systems in automatic transmission
control (AW30-40LE) ........................................
7A2-13
High speed CAN bus ..........................................
7A2-13
Diagnosis .................................................................
7A2-13
Electronic Diagnosis ...........................................
7A2-13
Check Trans Indicator ........................................
7A2-13
On Board Diagnostic Check ..............................
7A2-13
"Check Trans" Check .........................................
7A2-14
Tech 2 OBD Connection ....................................
7A2-17
Snapshot Display With TIS2000 .................. 7A2-23
Service Programming System (SPS)............. 7A2-27
OBD Diagnostic Management System ............
7A2-30
16 - Terminal Data Link Connector (DLC) ......
7A2-31
Clear DTC ............................................................
7A2-32
DTC Check ..........................................................
7A2-32
TCM Precaution ..................................................
7A2-32
Information On TCM ...........................................
7A2-32
TCM Diagnostic Trouble Codes ........................
7A2-33
DTC P0560 (FLASHING CODE 25)
System Voltage Error ...........................................
7A2-34

DTC P0602 (FLASHING CODE 63)
Transmission Control Module (TCM)
Programming Error ................................................
7A2-36
DTC P0705 (FLASHING CODE 17)
Transmission Range Sensor Circuit
Malfunction .............................................................
7A2-38
DTC P0712 (FLASHING CODE 15)
Transmission Oil Temperature Sensor
Circuit Low Input ....................................................
7A2-42
DTC P0713 (FLASHING CODE 16)
Transmission Oil Temperature Sensor
Circuit Hight Input ..................................................
7A2-45
DTC P0717 (FLASHING CODE 14)
Input Speed Sensor Signal Error .........................
7A2-48
DTC P0722 (FLASHING CODE 11)
Output Speed Sensor Signal Error .....................
7A2-51
DTC P0743 (FLASHING CODE 33)
Torque Converter Clutch Electrical .....................
7A2-54
DTC P0748 (FLASHING CODE 35)
Pressure Control Solenoid Electrical ..................
7A2-57
DTC P0753 (FLASHING CODE 31)
Shift Solenoid S1 Electrical ..................................
7A2-60
DTC P0758 (FLASHING CODE 32)
Shift Solenoid S2 Electrical ..................................
7A2-63
DTC P1767 (FLASHING CODE 67)
ECM CAN Invalid ...................................................
7A2-66
DTC P1790 (FLASHING CODE 61)
Transmission Control Module ROM
Checksum Error .....................................................
7A2-69
DTC P1791 (FLASHING CODE 62)
Transmission Control Module RAM
Error .........................................................................
7A2-71
DTC U2104 (FLASHING CODE 65)
CAN BUSS OFF ....................................................
7A2-73

7A2-2 TRANSMISSION CONTROL SYSTEM (AW30 –40LE) (V6 3.5L)

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, REFE
R
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, o
r
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 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.
 3rd Start mode –Starts in 3rd gear to reduce
slippage on ice or snow.
 Power mode has a delayed up shift when more
powerful acceleration is required.
Also, the built–in fail–safe function (“backup 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 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 powe
r
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.

7A2-10 TRANSMISSION CONTROL SYSTEM (AW30 –40LE) (V6 3.5L)

Control and Functions
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 S1 and the shift solenoid S2.
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
The clutch ON/OFF is controlled by moving the
converter clutch valve through shifting Torque
Converter Clutch (TCC) solenoid using the ON/OFF
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
Transmission Control Module (TCM) 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 othe
r
electronic modules, can be regulated by this function.
Fail –Safe Mechanism
If there is a problem in the transmission system, the
TCM will go into a “backup" 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 o
f
speed.
ATF Warning Control
The oil temperature sensor detects the ATF oil
temperature to control the oil temperature warning,
TCC, and the 3rd start mode.
Reverse Lock Out Control
With the selector lever in reverse position, the TCM will
not close the PWM solenoid until the vehicle is below
15 km/h (9.3 mph), thus preventing reverse
engagement above this speed.

Downhill Control
This mode is automatically activated from NORMAL
mode only when downhill conditions are recognized.
The shift pattern is identical to NORMAL mode except
3-4 and 4-3 shift lines at low throttle modified to get
engine braking on a larger speed range.
Uphill Control
When uphill condition are recognized the 2-3 and 3-4
shift and TCC apply are down only when the engine
torque is sufficient in order to avoid shift hunting.
Gear Shift Control 3rd start


SELECT LEVER RANGE SHIFT PATTERN
D(Drive) 1


2TCC

3TCC

4TCC
3(Third) 1

2TCC

3TCC
2(Second) 1

2(
3)
L(First) 1(
2)
TCC: Torque Converter Clutch
(Notice1): “( )" means over-revving prevention control.
Mode Type


Mode Type Select lever position
Normal drive mode
(NOR) Entire range (excluding “R")
Power drive mode
(PWR) Entire range (excluding “R")

Mode Selection



SWITCH(SW) LAMP
Mode Type PWR/N
OR.S 3RD
START SW POWER
DRIVE LAMP 3RD
START LAMP
Normal
drive mode
(NOR) OFF OFF OFF OFF
Power
drive mod
(PWR) ON OFF ON OFF
3rd Start
mode OFF ON OFF ON
However, the 3rd start switch prevails over the
PWR/NOR switch.
The mode become normal drive mode when the 3rd
start switch is operated from ON to OFF.

TRANSMISSION CONTROL SYSTEM (AW30 –40LE) (V6 3.5L) 7A2-11

Comparison of mode
1. The normal drive mode is set at the normal shift
points.
2. The shift points of the power drive mode are shifted
to the higher speed side, compared to the normal
drive mode.
3. The 3rd start mode is a special mode used
exclusively for starting in third gear.
3rd start Mode
1. The 3rd start switch will operate when switched on
after all of the following conditions are present:
a. The gear select position is “D" range only.
b. Vehicle speed is 11 km/h (7 mph) or less.
c. Transmission oil temperature is 120

C (248

F)
or less.
d. Accelerator opening is at 8% or less.
2. Cancel Release
1. Cancellation by driver
a. Turning off the 3rd start mode switch
b. Shifting select position to “3", “2", or “L" (3rd
start mode is not canceled by selecting “N",
“ R", or “P")
c. Ignition key is turned off.
2. Automatic cancellation
a. When vehicle runs at 34 km/h (21mph) o
r
more for 1 second or more
b. When transmission oil temperature reaches 120

C (284

F) or above
NOTE: The mode returns to normal drive mode o
r
power drive mode after the 3rd start 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 Transmission Control Module
(TCM).
The “CHECK TRANS" light flashes to alert the driver,
and the transmission must be manually shifted as
follows:


Select lever position Gear Ratio Selected
D 4 (Fourth)
Manual 3 4 (Fourth)
Manual 2 3 (Third)
Manual L 3 (Third)
R Reverse
Shifts are firmer to prevent clutch slip and consequent
wear. The fault should be corrected as soon as
possible.

TRANSMISSION CONTROL SYSTEM (AW30 –40LE) (V6 3.5L) 7A2-13

CAN bus systems in automatic
transmission control (AW30-40LE)
The automatic transmission control system in AW30-
40LE uses high speed CAN bus system .The individual
CAN bus systems are connected via two interfaces and
can exchange information and data. This allows control
modules that are connected to different CAN bus
systems to communicate.
High speed CAN bus
Transmission control modules in the vehicle that require
continuous, rapid communication are connected to the
high speed CAN bus. For example, the automatic
transmission is continuously notified of the current
engine load status. Since the automatic transmission
control module has to react immediately to load status
changes, rapid communication is required between the
engine control module and the automatic transmission
control module. The high speed CAN bus in the AW30-
40LE is designed as a two-wire CAN bus (twisted pair).
The wires are shielded and twisted. The transfer rate is
500 K baud.




RUW37ASF000401
Diagnosis
Electronic Diagnosis
How To Diagnose The Problem
1. To avoid incorrect diagnostics, this book needs to
be followed accurately. Unless stated, do not jump
directly to a section that could contain the
solution. Some important information may be
missed.
2. The sections in CAPITALS and bold are the main
sections that can be found in the contents.
3. The go to “
SECTION"
means to continue to check
going to the “section".
4. The go through “
SECTION"
means to go through
the “section" and then to go back to the place the
go through was written.
5. BASIC ELECTRIC CIRCUITS:
You should understand the basic theory o
f
electricity. This includes the meaning of voltage,
amps, ohms, and what happens in a circuit with an
open or shorted wire. You should also be able to
read and understand wiring diagrams.
Check Trans Indicator
Find CHECK TRANS indicator and verify if it is
A. Flashing: Go to DIAGNOSTIC CHECK.
B. Staying on: Go through CHECK TRANS CHECK
.
C. Is never ON when the ignition key is turned on: Go through CHECK TRANS CHECK
D. Is ON during 3 seconds at ignition but OFF after: Normal operation. No DTC or malfunction.



RTW37ASH000401
On Board Diagnostic Check
This test determines if the transmission or its input or
output connections or sensors are failing.
1. Connect the Tech 2: Go through Tech 2 OBD
CONNECTION .
2. Turn on the ignition but not the engine.
3. Push “F0" on Tech 2 to see the Diagnostic Trouble
Code (DTC):

7A2-22 TRANSMISSION CONTROL SYSTEM (AW30 –40LE) (V6 3.5L)

TRANSMISSION DATA
ITEM UNIT ENGIN RUNNING AT IDLE
Current Gear 1 st/2 nd/3 rd/4 th 1 st
Target Gear 1 st/2 nd/3 rd/4 th 1 st
Vehicle Speed km/h 0 km/h
AT Output Speed (Automatic Transmission) RPM 0 RPM
AT Input Speed (Automatic Transmission) RPM 675725 RPM
Engine Speed RPM 675725 RPM
Throttle Position Sensor Signal % 0.007.00%
AT Oil Temperature (Automatic Transmission) C Depends on conditions
TCM Status Transfer Low /Transfer High Transfer HI
Desired PC Solenoid Pressure (STH) kPa 34.397.0 kPa
Desired PC Solenoid Current (STH) mA 8351020 mA
PC Solenoid Actual Current (STH) mA 8351020 mA
Gear Ratio : 1 Depends on uper hood
TCC Slip Speed RPM 0 RPM
Shift Position Actual P/R/N/L/2/3 P
Inhibitor Switch P/R/N/L/2/3 P
Transmission Check Light On/Off Off
AT Oil Temperature Lamp (Automatic
Transmission) On/Off Off
3 rd Start Lamp On/Off Off
Power Lamp On/Off Off
Shift Solenoid S1 On/Off On
Shift Solenoid S2 On/Off On
Shift Solenoid S3 On/Off Off
Diag Switch Condition On/Off Off
Power Switch On/Off Off
Brake Switch On/Off Off
Cruise Switch On/Off Off
4L Signal On/Off Off
3 rd Start Switch On/Off Off
Coolant Temperature C Depends on conditions
Torque Request (timing Retard) CA 0 CA
Garage Shift Mode On/Off Off
CAN TPS % 0.00%
CAN Signal Valid Counter (ECM)
— 0  255
CAN Signal Valid Counter (TCM) — 0  255

7A2-44 TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L)

Diagnostic Aids

Inspect the wiring for poor electrical connection at
the TCM. Look for possible bent, backed out,
deformed or damaged terminals. Check for weak
terminal tension as well. Also check for a chafed wire
that could short to bare metal or other wiring. Inspect
for a broken wire inside the insulation.

When diagnosing for a possible intermittent short o
r
open condition, move the wiring harness while
observing test equipment for a change.
 Check oil temperature sensor for proper mounting
and adjustment.



DTC P0712 (FLASHING CODE 15) Transmission Oil Temperature Sensor
Circuit Low Input


Step Action Value(s) YES NO
1
Was the powertrain On-Board Diagnostic (OBD)
System Check performed? — Go to Step 2 Go to OBD
System Check
2 Perform the transmission fluid checking procedure.
Refer to checking Transmission Fluid level and
Condition in Automatic Transmission 7A section.
Was the fluid checking procedure performed ? — Go to Step 3 Refer to
Checking
Transmission
Fluid level and
Condition in
Automatic
Transmission
(AW30-40LE)
section
3

1. Install the scan tool.

2. Key “ON"
3. Review and record scan tool data.

4. Operate the vehicle with in scan tool data.
Does the scan tool indicate DTC P0712 ? — Go to Step 4 Refer to
Diagnostic Aids
4 Measure the voltage of the transmission fluid
temperature sensor by the J39200 DMM.

1. Key “OFF".
2. Disconnect the oil temperature sensor connector.

3. Key “ON".

4. Connect the J39200 DMM to the each terminal of
the oil temperature sensor connector E83-2 and
E83-1.
Does the scan tool indicate less than specified
value ? 5V Go to Step 5 Go to Step 6
5 Replace the transmission fluid temperature sensor.
Is the action complete ? — Verify repair —