Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual — part 303

AUTOMATIC TRANSMISSION (AW30-40LE) 7A-61

DTC P0743 (FLASHING CODE 33) TORQUE CONVERTER CLUTCH

CONTROL LOCK-UP (ON/OFF) SOLENOID FAILURE (SL) (Cont’d)

Step Action

Value(s)

Yes

No

10

Replace the lock-up solenoid (SL).
Is the replacement complete?



Go to Step 12



11

Check the wiring harness between the TCM 20
pin connector terminal (12) and A/T 8 pin
connector terminal (7) for ground shorted.
Was a problem found and corrected?



Go to Step 12



12

1. After the repair is complete, use the scan tool

to select "DTC", then "Clear Info" function.

2. Make a road running test for the vehicle.
3. Review the scan tool "DTC Info".

Has the last failed or is the current DTC
displayed?



Begin the
diagnosis

again.

Go to Step 1

System OK

7A-62 AUTOMATIC TRANSMISSION (AW30-40LE)

DTC P0748 (FLASHING CODE 35)

PRESSURE CONTROL SOLENOID FAILURE (STH)

UBS (For General Export)

D07R200062

TFR/S (For Australia) and TFR (For South Africa)

D07L200007

AUTOMATIC TRANSMISSION (AW30-40LE) 7A-63

‘01TFR (For Thailand)

D07L100010

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.

Fail-safe control:

The TCM controls fail-safe by detecting pressure
control solenoid failure.

Failure detection:

IG short failure

• When the feedback A/D value is more than 1020

for 500 milli-second continuously.

• Detection inhibit condition: Prohibition during 1

second after reversion from open failure, because
the possibility of the mis-detection is high.

Open failure (Including GND Short)

• When the feedback A/D value is less than 15 for

more than 70 milli-second continuously, judges as
faliure, and turns the current of target output off,
after 1.5 second passed turns the current of target
value to normal. The A/D value is checked, and this
operation is repeated during 70 milli-second again.

• When it continues for 12.5 second in total.

Contents of control:

At failure detection

• Lock-up control inhibit

• Up hill and down hill control inhibit (For UBS)

• Squat control inhibit

At failure decision

• Executes following items in addition to above

control items at failure detection.

• Turns Solenoid power supply OFF

• Blinks "CHECK TRANS" lamp

• Stores the failure information in failure memory

*Prohibits failure detection of S1, S2, SL, STH, selector
position switch, and oil temperature sensor.

Conditions of turning "CHECK TRANS" off:

Turns "CHECK TRANS" lamp off after ignition is turned
ON

→ OFF→ ON.

Reversion conditions from fail-safe:

At failure detection
When IG short failure···The feedback A/D value is

less than 1020 for 1 second continuously.

When open failure···Detection criteria is not

satisfied or the feedback A/D value is more than 15
for 1 second continuously.

At failure decision
Recovers at the same time as the conditions of

turning “CHECK TRANS” lamp off are satisfied.

Test description:

The following numbers correspond to the step numbers
on the diagnostic chart.
1. The solenoid resistance is within the range of 5 to

5.6

Ω. (at 20°C)

2. This test checks for shorted circuit at the TCM.

7A-64 AUTOMATIC TRANSMISSION (AW30-40LE)

Diagnostic aids:

An intermittent may be caused by a poor connection,
rubbed through wire insulation or a wire broken inside
the insulation. Inspect related harness connector for
backed out terminals, improper mating, broken locks,
improperly formed or damaged terminals, poor terminal
to wire connection and damaged harness.