engine ISUZU TF SERIES 2004 Workshop Manual

7A2-56 TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L)

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.5 (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
oropen condition, move the wiring harness while
observing test equipment for a change.


DTC P0743 (FLASHING CODE 33) Torque Converter Clutch Electrical


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

1. Install the scan tool.

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

4. Operate the vehicle within scan tool data.
Does the scan tool indicate DTC P0743? — Go to Step 3 Refer to
Diagnostic Aids
3

1. Key “ON", engine run.

2. Place the selector lever in the "P" range.
3. Measure the voltage between terminal C94-5 and
terminal C94-1 on the TCM pigtail connector by
J39200 DMM.
Is the voltage specified value? 816V Go to Step 4 Go to Step 10

7A2-62 TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L)

Action Taken When The DTC Sets

The TCM operates shifting as following pattern.



Normal Fail S1 S2
1 3 - on
2 3 - on
3 3 - on
4 4 - off

No squat control.
 No engine torque control.

No line pressure control.

No lock-up control.
 No slope control.

Check Trans ON.

DTC stored.

No detect DTC P0722

No detect DTC P0717

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.


DTC P0753 (FLASHING CODE 31) Shift Solenoid S1 Electrical


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

1. Install the scan tool.

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

4. Operate the vehicle within scan tool data.
Does the scan tool indicate DTC P0753? — Go to Step 3 Refer to
Diagnostic Aids
3

1. Key “ON", engine run.

2. Place the selector lever in the "P" range.
3. Measure the voltage between terminal C94-16 and
terminal C94-1 on the TCM pigtail connector by
J39200 DMM.
Is the voltage specified value? 816V Go to Step 4 Go to Step 10

TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L) 7A2-65

Action Taken When The DTC Sets
The TCM operates shifting as following patterns.



Normal Fail S1 S2
1 3 - on
2 3 - on
3 3 - on
4 4 - off

No squat control.
 No engine torque control.

No line pressure control.

No lock-up control.
 No slope control.

No torque reduction.

Check Trans ON.

DTC stored.

No detect DTC P0722.

No detect DTC P0717.

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.


DTC P0758 (FLASHING CODE 32) Shift Solenoid S2 Electrical


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

1. Install the scan tool.

2. Key “ON".

3. Review and record scan tool data.
4. Operate the vehicle within scan tool data.
Does the scan tool indicate DTC P0758? — Go to Step 3 Refer to
Diagnostic Aids
3

1. Key “ON", engine run.

2. Place the selector lever in the "P" range.
3. Measure the voltage between terminal C94-15 and
terminal C94-1 on the TCM pigtail connector by
J39200 DMM.
Is the voltage specified value? 816V Go to Step 4 Go to Step 10

TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L) 7A2-67

DTC P1767 (FLASHING CODE 67) ECM CAN Invalid

RTW37AMF000401

Circuit Description
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. Transmission control
modules in the vehicle that require continuous, rapid
communication are connected to the high speed CAN
bus. 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
transmission rate is 500K band.

Condition for setting the DTC
The TCM detects invalid signal for 0.18 sec. (After the
TCM leaves a communication start with the ECM fo
r
0.64 sec)
The TCM detects above condition for 2.0 sec
continuously.
Action Taken When The DTC Sets

The line pressure is max.
 The TCM judges APS(Accelerator Position Sensor)
angle is 0% at the time of shift operation.

No line pressure control.

No engine torque control.
 No lock-up control.

No slope control.

Check Trans ON.

DTC stored.

No squat control.

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.

7A2-74 TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L)

DTC U2104 (FLASHING CODE 65) CAN BUSS OFF

RTW37AMF000401

Circuit Description
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. Transmission control
modules in the vehicle that require continuous, rapid
communication are connected to the high speed CAN
bus. 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
transmission rate is 500K band.

Condition for setting the DTC
The TCM detects CAN BUS OFF for 0.18 sec (After the
TCM leaves a communucation start with the ECM fo
r
0.64 sec) continously..
Action Taken When The DTC Sets

The throttle pressure is max.

The TCM judges APS(Accelerator Position Sensor)
angle is 0% at the time of shift operation.
 No throttle pressure reduction.

No torque reduction.

No lock-up control.
 No slope control.

No squat control.

Check Trans ON.

DTC stored.

Engine REV is 7000 rpm.
 Coolant tempreature is 80

C.

7A3-12 ON-VEHICLE SERVICE (AW30 –40LE)

Manual Shifting Test
NOTE: With this test, it can be determined whether the
trouble lies within the electrical circuit or is a mechanical
problem in the transmission.
1. Disconnect TCM connector
Inspect manual driving operation
2. Inspect manual driving operation
Check that the shift and gear positions correspond
with the table.
If the “L", “2", “3" and “D" range gear positions are
difficult to distinguish, do perform the following road
test.
While driving, shift through the “L", “2", “3" and “D"
ranges. Check that the gear change corresponds to
the gear position.
If any abnormality is found in the above test, do
perform the stall, time lag or gear change tests.



RUW37ASH004101
3. Connect TCM connector
With the engine off, connect the TCM connector.


Stall Test



RUW37ALH000101
The object of this test is to check the overall
performance of the transmission and engine b
y
measuring the maximum engine speeds at the “D" and
“ R" ranges.
NOTE:
1. Perform the test at normal operation fluid
temperature (50 – 80 
C or 122 – 176 
F).
2. Do not continuously run this test longer than 5 seconds.

ON-VEHICLE SERVICE (AW30 –40LE) 7A3-13

Measure Stall Speed
1. Chock the four wheels.
2. Mount an engine tachometer.
3. Fully apply the parking brake.
4. Step down strongly on the brake pedal with your left foot.
5. Start the engine.
6. Turn off the A/C.
7. Shift into the “D" range. Step all the way down on
the accelerator pedal with your right foot. Quickl
y
read the highest engine rpm.
Stall speed: 2100






150 rpm
8. Perform the same test in the “R" range.
Evaluation

1. If the engine speed is the same for both ranges but
lower than the specified value:
 Engine output is insufficient.
 Stator one-way clutch is not operating properly.
NOTE: If more than 600 rpm below the specified value,
the torque converter could be faulty.
2. If the stall speed in “D" range is higher than
specified:
 Line pressure too low
 Forward clutch slipping
 No.2 one-way clutch not operating properly
3. If the stall speed in “R" range is higher than
specified:
 Line pressure too low
 Direct clutch slipping
 No.3 brake slipping
4. If the stall speed in the “R" and “D" ranges are
higher than specified:
 Line pressure too low
 Improper fluid level

Time Lag Test



F07RY00003
If the shift lever is shifted while the engine is idling,
there will be a certain time elapse or lag before the
shock can be felt. This is used for checking the
condition of the forward clutch, direct clutch, No.3
brake, and No.2 one-way clutch.
NOTE:
1. Perform the test at normal operation fluid
temperature (50 – 80 C or 122 – 176 F)
2. Be sure to allow one minute interval between tests.
3. Make three measurements and take the average value.

7A3-14 ON-VEHICLE SERVICE (AW30 –40LE)

Measure Time Lag
1. Fully apply the parking brake.
2. Start the engine. Check idling speed (A/C OFF).
3. Shift the shift lever from “N" to “D" range. Using a
stopwatch, measure the time it takes from shifting
the lever until the shock is felt.
Time lag: Less than 0.7 seconds
4. In same manner, measure the time lag for “N"


“R".
Time lag: Less than 1.2 seconds
Evaluation
1. If “N" 
“ D" time lag is longer than specified:

Line pressure too low
 Forward clutch malfunction
 No.2 one-way clutch not operating properly
2. If “N" 
“ R" time lag is longer than specified:

Line pressure too low
 Direct clutch malfunction
 No.3 brake malfunction
3. If both time lag is longer than specified:

Line pressure too low

Hydraulic Test



RUW37ALH000201
Preparation

1. Warm up the transmission fluid.
2. Remove the transmission case test plug and mount the hydraulic pressure gauge.
Oil pressure gauge: J –29770 –A
NOTE: Perform the test at normal operation fluid
temperature (50 – 80 
C or 122 – 176 
F).

ON-VEHICLE SERVICE (AW30 –40LE) 7A3-15

Measure Line Pressure
1. Fully apply the parking brake and chock the four
wheels.
2. Start the engine and check idling rpm.
3. Shift into “D" range, step down strongly on the brake
pedal with your left foot and, while manipulating the
accelerator pedal with the right foot, measure the
line pressures at the engine speeds specified in the
table.
4. In the same manner, perform the test in “R" range.


Line pressure kPa (kg/cm2/psi) Engine
speed “D" range “R" range
Idling 323 – 382
(3.3 – 3.9/47 – 55) 500 – 598
(5.1 – 6.1/73 – 87)
Stall 1,137 – 1,274 (11.6–13.0/165–185) 1,499 – 1,833
(15.3–18.7/218–266)
Evaluation
1. If the measured values at all ranges are higher than
specified:

Pressure control solenoid defective
 Primary regulator valve defective
2. If the measured values at all ranges are lower than
specified:

Primary regulator valve defective
 Oil pump defective
 Pressure control solenoid defective
3. If pressure is low in “D" range only:

“ D" range circuit fluid leakage
4. If pressure is low in “R" range only:

“ R" range circuit fluid leakage
Road Test
NOTE: Perform the test at normal operation fluid
temperature (50 – 80 
C or 122 – 176 
F).
“D" Range Test in “NORMAL", and
“POWER" Pattern Ranges
Shift into the “D" range and hold the accelerator pedal
constant at the 50% and 100% throttle valve opening
positions.
Push in one of the pattern selector buttons and check
the following:

1. 1 –2, 2 –3, 3 –OD and lock-up, up-shifts should take
place, and shift points should conform to those
shown in the automatic shift diagram.


RUA370MH000101




RUA37ASH000101