2004 ISUZU TF SERIES Tcm

7A2-54 TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L)

Step Action Value(s) YES NO
4 Measure the resistance of wire by the J39200 DMM.

1. Key “OFF".

2. Disconnect the TCM connector.
3. Connect the output revolution sensor connector.

4. Measure the resistance between the TCM terminal
C95-5 and C95-14
Does the scan tool indicate specified value ? 560680
(2
0
C) Go to Step 5 Go to Step 6
5

1. Replace the TCM

2. Install the scan tool (TECH2).
3. Make a road running test for the vehicle.
Important:
The replacement TCM must be
programmed. (Refer to SPS for procedure.)
Does the scan tool indicate DTC P0722 ? — Go to Step 7 Go to Step 8
6 Measure the resistance of output revolution sensor by
the J39200 DMM.

1. Key “OFF"
2. Disconnect the output revolution sensor connector.

3. Measure the resistance between terminal output
revolution sensor side connector E81-1 and E81-
2.
Does the scan tool indicate specified ? 560680
(2
0

C) Go to Step 9 Go to Step 7
7 Replace the output revolution sensor.
Is the action complete ? — Verify repair —
8 Replace the TCM.
Important:
The replacement TCM must be
programmed. (Refer to SPS for procedure.)
Is the action complete ? — Verify repair —
9 Check the wire between terminal C95-5 and E81-1 or
C95-14 and E81-2.

1. Connect the J39200 DMM to the each the TCM
connector and output revolution sensor.
If the problem found repair as necessary.
Was the found problem ? — Verify repair —

TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L) 7A2-55

DTC P0743 (FLASHING CODE 33) Torque Converter Clutch Electrical


RUW37ALF000601
Circuit Description
The lock-up solenoid SL of the torque converter clutch
(TCC) controls the lock-up clutch by a signal according
to the lock-up range judgment of the TCM when the
vehicle runs.
This function can improve the fuel consumption to
almost the same extent as the manual transmission.
The lock-up solenoid SL is put into B+ by the TCM, so
that the solenoid is actuated with the result of lock-up.
Condition for setting the DTC
The TCM detects following conditions both "Condition
1" and "Condition 2" occur 2 times or more than it.
Condition 1 ("GND short"):

Voltage at connector pin is 0V for 0.3 sec
continuously when solenoid is “ON".
Condition 2 ("Open or IG short"):

Voltage at connector pin is ignition voltage for 0.5
sec continuously when solenoid is “OFF".
Action Taken When The DTC Sets

No lock-up control.
 The TCM fixes to 1st gear when the vehicle speed is
less than 6 mph.

Check Trans ON.

DTC stored.

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

TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L) 7A2-57

Step Action Value(s) YES NO
4

1. Key "OFF".

2. Disconnect the TCM connector (C-94).
3. Key "ON".

4. Measure the voltage between terminal C94-5 and
terminal C94-1 by J39200 DMM.
Is the voltage specified value? 0V Go to Step 5 Go to Step 7
5

1. Key “OFF".

2. Measure the resistance between terminal C94-5
and body ground by J39200 DMM.
Is the resistance specified value? 
Go to Step 9 Go to Step 6
6

1. Disconnect the automatic transmission connector
(E-82).

2. Measure the resistance between terminal E82-7
and body ground by J39200 DMM.
Is the resistance specified value? 
Go to Step 7 Go to Step 8
7

1. Check for open or short in the wire between
terminal C94-5 and terminal E82-7.

2. Repair or replace the wire between terminal C94-5
and terminal E82-7.
Is the action complete? — Verify repair —
8 Replace the SL solenoid.
Is the action complete? — Verify repair —
9

1. Clear the DTC.

2. Perform the test-driving.
3. Check the DTC.
Was DTC P0743 stored? — Go to Step 10 Refer to
Diagnostic Aids
10 Replace the TCM.
Is the action complete? — Verify repair —

7A2-58 TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L)

DTC P0748 (FLASHING CODE 35) Pressure Control Solenoid Electrical



RTW37ALF000601
Circuit Description
The pressure control solenoid is a PWM duty control
solenoid located in the valve body.
The pressure control solenoid is a TCM-controled
device used to regulate transmission throttle pressure
by energizing current from the TCM.
Condition for setting the DTC
The TCM detects following "Condition 1" and "Condition
2".
Condition 1("Ignition short"):

When the TCM detects following condition for 0.5
sec continuously.

Monitor A/D value is more than 1000 (1.36A).
Condition 2("Open or GND short"):

When the TCM detects following condition for 70
msec continuously.

Monitor A/D value is less than 15 (20mA).
Action Taken When The DTC Sets

No squat control.
 No line pressure control.

No lock-up control.

No slope control.
 Check Trans ON.

TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L) 7A2-59


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.
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 P0748 (FLASHING CODE 35) Pressure Control Solenoid Malfunction


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 P0748? — Go to Step 3 Refer to
Diagnostic Aids
3 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 4 Refer to
checking
Transmission
Fluid level and
Condition in
Automatic
Transmission
(AW30-40LE)
section

7A2-60 TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L)

Step Action Value(s) YES NO
4 Measure the resistance of pressure control solenoid.

1. Key “OFF".
2. Disconnect the automatic transmission connector
and TCM connector.

3. Measure the resistance between automatic
transmission terminal E82-2 and automatic
transmission terminal E82-6.
Is the resistance specified value? 5 to 5.6
at
68
F (20
C)Go to Step 5 Go to Step 8
5 Measure the resistance of wire between terminal
C94-2 and terminal C94-4

1. Key “OFF".
2. Connect the automatic transmission connector.

3. Disconnect the TCM connector.

4. Measure the resistance between terminal C94-2
and terminal C94-4.
Is the resistance specified value? 5 to 5.6
at
68
F (20
C)Go to Step 7 Go to Step 6
6 Repair or Replace the wire between terminals C94-
2,4 and terminals E82-6,2.
Is the action complete? — Verify repair —
7 Observe the pressure control solenoid valve data on
the scan tool data.

1. Key “ON".
Does the scan tool indicate is specified value? 1.0- Verify repair Go to Step 9
8 Replace the pressure control sorenoid.
Is the action complete? — Verify repair —
9 Replace the TCM.
Important:
The replacement TCM must be
programmed (Refer to SPS for procedure).
Is the action complete? — Verify repair —

TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L) 7A2-61

DTC P0753 (FLASHING CODE 31) Shift Solenoid S1 Electrical



RTW37ALF000601

Circuit Description
The shift solenoi S1 changes the hydraulic route with
the signals from the TCM according to the vehicle
speed and the throttle opening to control shifting. When
the solenoid S1 or S2 fails, the hydraulic circuit is
mechanically operated as a backup.

Condition for setting the DTC
The TCM detects following "Condition 1" and "
Condition 2" for 2 times continuously at shifting.
Condition 1("GND short"):

Voltage at connector pin is 0V for 0.3 sec
continuously when solenoid is “ON".
Condition 2("Open or Ignition short"):

Voltage at connector pin is ignition voltage for 0.5
sec continuously when solenoid is “OFF".