Timing ISUZU TF SERIES 2004 Workshop Manual

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.

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

CONSTRUCTION AND FUNCTION 7A1-27
Item Description
- 4L mode -
4L mode setting condition
4L switch: On
Vehicle speed: More than 5km/h
Above conditions are met at the same time.
4L mode reset condition
4L switch: Off
Vehicle speed: Less than 4km/h
Above conditions are met at the same time.

- Down slope mode -
Down slope mode setting condition
Brake switch: On
Engine idle condition: More than 2.5 seconds
Select lever position: D or 3 range
Vehicle speed: More than 55km/h
Vehicle speed change: More than 1km/h
Above conditions are met at the same time.
Down slope mode reset condition
Engine idle condition: Not idle condition
Select lever position: Other than D or 3 range
At least, one of above conditions is met.

- Power Mode -
When power drive switch is On at only D range or 3 range, the shift change is performed by
1 – 4 speed based on shift diagram set as power pattern.

- Up slope mode -
Up-slope reasoning value is calculated from the average throttle angle and the average
acceleration. Otherwise, up-slope reasoning value is calculated from the vehicle speed.
TCM judges as up-slope mode when the former is bigger than latter.


Lock-up control The lock-up solenoid adjusts the pressure based on the signal from the TCM according to
the vehicle speed, throttle opening and other input signals based on the pre-set lock-up
point to control the lock-up.
Smooth lock-up control engages and disengages the clutch smoothly at the time of lock-up.
When the oil temperature is low (below 20
C) or high (above 128
C), lock-up is prohibited
even when the vehicle is at a lock-up speed.
The lock-up is disengaged also when the throttle is closed.
Direct electronic shift
control (DESC)
The duty cycle type solenoid is used for each clutch and brake. The solenoid adjusts the
clutch pressure to be suited to the engine load and vehicle traveling condition based on the
signal from the TCM. The pressure switch provided in the control valve oil passage sends
the oil pressure condition to the TCM to control the disengagement and engagement of the
clutch and brake directly and finely.
Learning control Learning is controlled to correct the oil pressure control timing to engage or disengage the
clutch optimally in order to compensate changes of the engine performance and changes
of the transmission with time. It is controlled to bring the speed-change time closer to the
value pre-set to the TCM.

CONSTRUCTION AND FUNCTION 7A1-33
LEARNING CONTROL

Oil pressure control timing is optimally corrected at the time of clutch engagement and disengagement
and controlled to bring the speed-change time to the value preset to the TCM and compensate the
changes of the engine performance and changes of the transmission with time.

When the gear is shifted, the clutch pressure 2 is optimally corrected so that the speed-change time is as
near as the target value
1 preset to the TCM and the changes in the engine performance and the
changes of the transmission with time can be compensated based on the past speed-change results.

When the clutch is operated to shift the gear, the time of the clutch oil pressure release timing 4 on the
disengagement side is optimally corrected so that the changes of the engine rpm
3 is optimum.


Note:

When the battery terminal is disconnected, contents of learning are cleared and resultantly the speed
change shock may increase. After the vehicle has traveled, learning is repeated and the shock
decreases gradually.





Figure 53. Learning Control

DIAGNOSIS (JR405E) 7A2-97
No. B2: Poor Acceleration at Starting

Description:

Starting acceleration is poor.

Diagnosis Hints:

In addition to the low engine output, faulty gear shifting of AT or fixing at the 3rd position may be possible.
Therefore, in case of such a trouble that "maximum speed is low, and acceleration is poor", it should be cleared
up whether the trouble is originated from the engine system of AT system by a running test, inspection of stall
revolution, etc.

Possible Cause:

Clogged air cleaner, out of injection timing, dropped compression pressure, etc.

Fixing at 3rd position (fail-safe activated).
Since the gear is fixed at the 3rd position because of the fail-safe function, a trouble that "Maximum
speed is low, and acceleration is poor" is resulted. In this case, the DTC is memorized.
When TCM stops operation because of faulty TCM ground, the gear is fixed at the 3rd position because
of a mechanical reason. In this case, no DTC is memorized.

Disordered inhibitor switch.

Incorrect properties of throttle opening signal (serial communication) of throttle position sensor.
Throttle opening signal (serial communication) of the throttle position sensor does not change in
proportion to the throttle opening. In this case, fixing at the high or low gear results in such a trouble
that "Maximum Speed is Low and Acceleration is Poor".

Slip of clutch (low clutch, high clutch).

If slip of clutch is caused, a DTC (gear ratio error) is stored.

Dropped line pressure.

Trouble in the torque converter system (faulty operation).

Step Action Yes No
1 Test Drive.
Is the gear smoothly shifted in the order of 1st to 2nd, 2nd to 3rd,
3rd to 4th gear and lock up?

Clogged air cleaner,
out of injection
timing, dropped
compression
pressure, etc.

Go to Step 2
2 Gear ratio trouble diagnosis.
Travel in the following sequence for about 7 seconds or more in
each range: Start in the L range (1st) to 2 range (2nd) to 3 range
(3rd) to D range (4th) (to detect the gear ratio trouble exactly, this
process should be carried out)
Go to Step 3 Go to Step 3
3 Are any DTCs stored?
Go to DTC Chart Go to Step 4

DIAGNOSIS (JR405E) 7A2-127
No. F1: Low Maximum Speed or Poor Acceleration

Description:

Starting acceleration is poor.

Acceleration is slow though the accelerator pedal is stepped on during the running.

Diagnosis Hints:

In addition to the low engine output, faulty gear shifting of AT or fixing at the 3rd position may be possible.
Therefore, in case of such a trouble that "maximum speed is low, and acceleration is poor", it should be cleared
up whether the trouble is originated from the engine system of AT system by a running test, inspection of stall
revolution, etc.

Possible Cause:

Clogged air cleaner, out of injection timing, dropped compression pressure, etc.

Fixing at 3rd position (fail-safe activated).
Since the gear is fixed at the 3rd position because of the fail-safe function, a trouble that "Maximum
speed is low, and acceleration is poor" is resulted. In this case, the DTC is memorized.
When TCM stops operation because of faulty TCM ground, the gear is fixed at the 3rd position because
of a mechanical reason. In this case, no DTC is memorized.

Disordered inhibitor switch .

Incorrect properties of throttle opening signal (serial communication) of throttle position sensor.
Throttle opening signal (serial communication) of the throttle position sensor does not change in
proportion to the throttle opening. In this case, fixing at the high or low gear results in such a trouble
that "Maximum Speed is Low and Acceleration is Poor".

Slip of clutch (low clutch, high clutch).

If slip of clutch is caused, a DTC (gear ratio error) is stored.

Dropped line pressure.

Trouble in the torque converter system (faulty operation).

Step Action Yes No
1 Test Drive.
Is the gear smoothly shifted in the order of 1st to 2nd, 2nd to 3rd,
3rd to 4th gear and lock up?
Clogged air
cleaner, out of
injection timing,
dropped
compression
pressure, etc. Go to Step 2
2 Gear ratio trouble diagnosis.
Travel in the following sequence for about 7 seconds or more in
each range: Start in the L range (1st) to 2 range (2nd) to 3 range
(3rd) to D range (4th) (to detect the gear ratio trouble exactly, this
process should be carried out)
Go to Step 3 Go to Step 3
3 Are any DTCs stored?
Go to DTC Chart Go to Step 4

7A2-132 DIAGNOSIS (JR405E)
No. G3: Creep Force is small

Description:

Vehicle does not move though a run range is selected on a flat road during the idling.

Diagnosis Hints:

When the creep force is small in all ranges, low engine output is considered. Another possible cause is slip of
clutch. If the creep is normal only in the R range, operation of the fail-safe function due to a trouble in the electrical
system is considered.

Possible Cause:

Slip of clutch (low clutch).
If slip of clutch is caused, a DTC (gear ratio error) is stored.

Low engine output (low idling speed, out of injection timing, lowered compression pressure, etc.).

Shortage or faulty quality of ATF.

Disconnection or short circuit of solenoid valve output.

Clogged oil passage of solenoid valve output.

Faulty ground return line in AT assembly.
If the ground return line earth is faulty, clutch pressure may decrease causing slip of the clutch.

Trouble in the torque converter system (faulty operation).

Step Action Yes No
1 Gear ratio trouble diagnosis.
Travel in the following sequence for about 7 seconds or
more in each range: Start in the L range (1st) to 2 range
(2nd) to 3 range (3rd) to D range (4th) (to detect the gear
ratio trouble exactly, this process should be carried out)
Go to Step 2 Go to Step 2
2 Are any DTCs stored?
Go to DTC Chart Go to Step 3
3 Are the quantity, contamination and smell normal? If the ATF level is low,
replenish up to the
specified level.

Go to Step 4
If ATF is extremely
black and
contaminated and
smells burnt, slip of the
clutch is supposed.
Overhaul the AT unit.
4 Are the idling speed and other engine system normal?
Go to Step 5
Repair the defect or
replace.
5 Is the stall revolution normal in D, 3, 2 and L range? Refer
the STALL TEST section in this manual.
Go to Step 6
Repair the defect or
replace.
6 Is the line pressure normal? Refer the LINE PRESSURE
TEST section in this manual. Trouble in the AT
assembly or control
valve.
Repair the defect or
replace.