2004 ISUZU TF SERIES oil change

7D1-34 TRANSFER CONTROL SYSTEM

Diagnosis
Before determining a trouble (Non-trouble mode)
1. When shifting from 2H to 4H:
1-1-1 When the flashing frequency of the 4WD indicator is changed from 2Hz to 4Hz (Shft on the fly)
If the load is too large to shift the gears synchronously, the operation is repeated up to 3 times. If the shifting
is not effected after being repeated 3 times, the indicator frequency is changed from 2Hz to 4Hz and, at the
same time, the actuator condition is changed to 2H, indicator flashes at 4Hz for 10 seconds, and then goes
out.
Cause of excessive synchronous shifting load

Extremely low temperature (the oil viscosity of the front differential increases requiring a large load for
synchronization)
 High speed (since the difference of relative revolutions of gears to be shifted synchronously is too large,
required work load per unit time becomes larger).
Step 1-1-1:
Stop the vehicle or decrease the speed and operate as required again.

1-1-2 When the flashing frequency of the 4WD indicator is changed from 2Hz to 4Hz (Rigid and free wheel
Hub) / Block out of meshing spline.
Step 1-1-2:
Run the vehicle forward and backward several meters and operate as required again.

1-2 When the flashing of 4WD indicator at 2Hz continues more than 11.5 seconds (repetition of 3 times of
above No.1 is counted) (Shift on the fly)
If there is difference of revolutions and phases between the front wheel and axle, connecting the front wheel
and axle is difficult.
Until shifting in the transfer and connection of the front wheel and axle are completed

, the indicator flashes
at a frequency of 2Hz. In the above case, the indicator continues flashing at a frequency of 2Hz until the
connection of the front axle is completed. (If the shifting in the transfer is not completed, the flashing
frequency is changed to 4Hz (above No.1).)
By correcting the difference of relative revolutions and deviation of phases, the shifting can be completed.
Step 1-2:
While the vehicle is running, make sure of safety around the vehicle and accelerate or decelerate the
vehicle while going straight.
When the vehicle is at a stop, run the vehicle forward and backward several meters.

2.
When shifting from 4H to 2H
2-1 When 4WD indicator continues flashing at 2Hz
When shifting from 4H to 2H, the 4WD indicator continues flashing at 2Hz until separation in the transfer and
the separation of the front wheel axle are completed
. When torsional torque is accumulated in the drive
system, separation in the transfer and separation of the front axle
is difficult. In such a case, they can be
separated by removing the torsional torque of the drive system.
Step 2-1:
While the vehicle is running, make sure of safety around the vehicle and accelerate or decelerate the
vehicle while going straight.
When the vehicle is in stop, run the vehicle several meters forward and backward.


: Shift on the fly only.

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) 7A2-43

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

RTW37AMF000201
Circuit Description
The oil temperature sensor is a thermistor sensor that
is installed in the transmission case and converts
temperature changes into continuous electric signals,
then outputs them to the Transmission Control Module
(TCM). When the ATF temperature is low, the
resistance of the sensor (thermistor) goes up, so that
the voltage of the TCM signal becomes high.
As the ATF is gradually warmed, the resistance of the
sensor goes down and the voltage becomes low. At the
normal operating ATF temperature (80

C/176

F) of the
transmission, the voltage of the TCM is about 3.7V.
Condition for setting the DTC

The TCM detects following "Condition" for 5 min
continuously.
Condition ("Short"):

Oil temperature is more than 220

C (428

F).

Action Taken When The DTC Sets

The TCM judges oil temperature is 100

C (212

F).
 Check Trans ON.

DTC stored.
Conditions For Clearing The DTC

The DTC can be cleared from the TCM history by
using a scan tool.
 The DTC will be cleared from history when the
vehicle has achieved 40 warm-up cycles without a
failure reported.

After more than 1 second has elapsed after the
ignition key has been turned “ON", short between
No.11 and No.4 (ground) of DLC (Data Link
Connector). Then, after 1 second, but within 6
seconds, discontinue shorting.

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 —

7A2-46 TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L)

DTC P0713 (FLASHING CODE 16) Transmission Oil Temperature Sensor
Circuit Hight Input

RTW37AMF000201
Circuit Description
The oil temperature sensor is a thermistor sensor that
is installed in the transmission case and converts
temperature changes into continuous electric signals,
then outputs them to the Transmission Control Module
(TCM). When the ATF temperature is low, the
resistance of the sensor (thermistor) goes up, so that
the voltage of the TCM signal becomes high.
As the ATF is gradually warmed, the resistance of the
sensor goes down and the voltage becomes low. At the
normal operating ATF temperature (80

C/176

F) of the
transmission, the voltage of the TCM is about 3.7V.
Condition for setting the DTC

The TCM detects following "Condition" for 15 min
from ignition ON.
Condition ("Open"):

Fluctuation of high temperature fixed value is
2.3

C (36

F).
 Fluctuation of low temperature fixed value is -10

C
(14
F).
Action Taken When The DTC Sets

The TCM judges oil temperature is 100

C (212

F).

Check Trans ON.
 DTC stored.
Conditions For Clearing The DTC

The DTC can be cleared from the TCM history by
using a scan tool.

The DTC will be cleared from history when the
vehicle has achieved 40 warm-up cycles without a
failure reported.

After more than 1 second has elapsed after the
ignition key has been turned “ON", short between
No.11 and No.4  (ground) of DLC (Data Link
Connector). Then, after 1 second, but within 6
seconds, discontinue shorting.

TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L) 7A2-47

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 P0713 (FLASHING CODE 16) Transmission Oil Temperature Sensor
Circuit Hight 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 Automatic Transmission7A section.
Was the fluid checking procedure performed ? — Go to Step 3 Refer to
checking
Transmission
Fluid Level and
Condition
Automatic
Transmission
(AW30-40LE)
section
3

1. Install the scan tool ?

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

4. Operate the vehicle with in scan tool data.
Does the scan tool indicator DTC P0713 ? — Go to Step 4 Go to
Diagnostic Aids
4 Observe the voltage of the transmission fluid
temperature sensor on the TECH2 data.

1. Key “OFF".

2. Disconnect the transmission fluid temperature
sensor connector E-83
3. Install a fused jumper wire from terminal E83-2 to
E83-1 on the mission harness.

4. Key “ON".
Does the scan tool indicate more than specified
value ? 0.4V Go to Step 5 Go to Step 6
5 Replace the transmission fluid temperature sensor .
If the action complete ? — Verify repair —

7A2-68 TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L)


 Engine REV is 7000 rpm.

Coolant tempreature is 80

C.

No detect DTC P0712, 0713.
 No detect DTC P0560.
Conditions For Clearing The DTC

The DTC can be cleared from the TCM history by
using a scan tool.
 The DTC will be cleared from history when the
vehicle has achieved 40 warm-up cycles without a
failure reported.

After more than 1 second has elapsed after the
ignition key has been turned “ON", short between
No.11 and No.4 (ground) of DLC (Data Link
Connector). Then, after 1 second, but within 6
seconds, discontinue shorting.
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.

Inspect the wiring for EMI (Erectro-Magnetic
Interference). Check that all wires are properly
routed away from coil, and generator. Also check fo
r
improperly installed electrical options. When this test
is performed, turn “OFF" on electronic autoparts
switches to improperly for a noise preventing.

TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L) 7A2-75


 No detect DTC P1767.

No detect DTC P0560.

No detect DTC P0712, 0713.
Conditions For Clearing The DTC

The DTC can be cleared from the TCM history by
using a scan tool.
 The DTC will be cleared from history when the
vehicle has achieved 40 warm-up cycles without a
failure reported.

After more than 1 second has elapsed after the
ignition key has been turned “ON", short between
No.11 and No.4 (ground) of DLC (Data Link
Connector). Then, after 1 second, but within 6
seconds, discontinue shorting.
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.

Inspect the wiring for EMI (Erectro-Magnetic
Interference). Check that all wires are properly
routed away from coil, and generator. Also check fo
r
improperly installed electrical options. When this test
is performed, turn “OFF" on electronic auto parts
switches to improperly for a noise preventing.