Opel Frontera UBS. Manual - part 2540

AUTOMATIC TRANSMISSION (AW30-40LE)

7A–23

INTERMITTENT CONDITIONS

If the Tech2 displays a code as intermittent, or if after a
test drive a code does not reappear, the problem is most
likely a faulty electrical connection or loose wiring.
Terminals should always be the prime suspect.
Intermittent rarely occur in sophisticated electronic
components such as the Transmission Control Module
(TCM).
When an intermittent problem is encountered, check
suspect circuits for:

• Poor terminal to wire connection.

• Terminals not fully seated in the connector body

(backed out).

• Improperly formed or damaged terminals.

• Loose, dirty, or corroded ground connections.

HINT: Any time you have an intermittent in more than
one circuit, check whether the circuits share a
common ground connection.

• Pinched or damaged wires.

• Electro-Magnetic Interference (EMI)

HINT: Check that all wires are properly routed away

from spark plug wires, distributor wires, coil,
and generator. Also check for improperly
installed electrical options, such as lights, 2-
way radios, etc.

Use the F2: SNAPSHOT mode of the Tech2 to help
isolate the cause of an intermittent fault. The snapshot
mode will record information before and after the
problem occurs. Set the snapshot to "trigger" on the
suspect code (or codes) or, if you notice the reported
symptom during test drive, trigger the snapshot
manually.
After the snapshot has been triggered, command the
Tech2 to play back the flow of data recorded from each
of the various sensors. Signs of an intermittent fault in a
sensor circuit are a sudden unexplainable jump in data
values out of the normal range.

7A–24

AUTOMATIC TRANSMISSION (AW30-40LE)

826RY00004

IDENTIFICATION OF TRANSMISSION
CONTROL MODULE (TCM)

ISUZU Part No: 8-97230-821-0

AUTOMATIC TRANSMISSION (AW30-40LE)

7A–25

DIAGNOSTIC TROUBLE CODES (DTC) CHECK

DTC
NUMBER

FLASHING
CODE

DESCRIPTION

P0120

21

ANALOG THROTTLE SIGNAL FAILURE (VTH)

P0502

24

SPEED METER SENSOR FAILURE (SP1)

P0705

17

GEAR SELECTOR FAILURE (PRND2L)

P0710

16

OIL TEMPERATURE SENSOR FAILURE (OT2)

P0717

14

INPUT REVOLUTION SENSOR FAILURE (NC0)

P0722

11

OUTPUT REVOLUTION SENSOR FAILURE (SP2)

P0727

13

ENGINE REVOLUTION SIGNAL FAILURE (NE)

P0743

33

TORQUE CONVERTER CLUTCH CONTROL LOCK-UP (ON/OFF) SOLENOID
FAILURE (SL)

P0748

35

PRESSURE CONTROL SOLENOID FAILURE (STH)

P0753

31

SOLENOID 1 FAILURE (S1)

P0758

32

SOLENOID 2 FAILURE (S2)

P1121

23

ANALOG THROTTLE SIGNAL FAILURE (VREF, VGND)

7A–26

AUTOMATIC TRANSMISSION (AW30-40LE)

DTC P0120 (FLASHING CODE 21) ANALOG THROTTLE SIGNAL FAILURE (VTH)

D07RY00023

Circuit description:
When the signal of the engine throttle position sensor
located on the accelerator pedal is supplied to the TCM,
the TCM judges the opening condition of the throttle.
The shift point of the transmission is determined by this
opening condition of the throttle.

Fail-safe control:
The TCM controls fail-safe by detecting analog throttle
signal (VTH) failure.

Failure detection:

•When the throttle input voltage is detected less than

0.112V or more than 4.417V for 2.0 seconds.

Contents of control:
At failure detection

•Throttle opening for line pressure control ... Throttle

opening 100%

•Throttle opening for shift control ... Throttle opening

0%

•Lock-up control inhibit

•Up hill and down hill control inhibit

•Squat control inhibit

At failure decision

Executes following items in addition to above control
items at failure detection.

•Blinks "CHECK TRANS" lamp

•Stores the failure information in failure-memory

Conditions of turning "CHECK TRANS" lamp off: 
Turns “CHECK TRANS” lamp off when judged 0km/h by
output revolution sensor after throttle signal input voltage
is detected more than 0.112V and less than 4.717V.
(however, uses 0 km/h judgment by back-up vehicle
speed at output revolution failure)

Reversion conditions from fail-safe:
At failure detection

Immediately recovers when the throttle input voltage
is detected more than 0.112V and less than 4.717V.

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 circled numbers on
the diagnostic chart.

(1) Check that the throttle input voltage is 0.25 to 0.45V.

(2) At this test, check that as the throttle opens, the

voltage goes up and that the voltage reaches 3.74 to
4.56V at the full open status.

(3) Check the power supply voltage (4.75 – 5.25V) of the

throttle position sensor.

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.