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

7A-42 AUTOMATIC TRANSMISSION (AW30-40LE)

‘01TFR (For Thailand)

D07L200011

Circuit description:

The neutral start switch gives the signals related to the
selector lever position (PRND2L) to the Transmission
Control Module (TCM). The neutral start switch turns
on when the select lever is shifted to the P, R, N, D, 2
or L range. The neutral start switch, which is connected
to the starter switch circuit, is available only when the
select lever is in the P or N range
The neutral start switch is connected to the
transmission manual shaft and installed in the
transmission case.

Fail-safe condition:

The TCM controls fail-safe by detecting selector
position switch failure.

Failure detection:

(1) OPEN:

• When all switches are OFF

• When the failure criteria continues for 30 seconds if

the vehicle speed which is calculated by output
revolution sensor is more than 30 km/h and the
engine revolution is more than 1500 rpm.

(2) SHORT:

• When more than two switches are ON at the same

time.

• When the failure criteria condition for 10 seconds.

Contents of control:

At failure detection
(1) OPEN: D range judgment
(2) SHORT: Judged by priority D>2>L>R>N>P

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

• Winter mode inhibit (For UBS)

At failure decision

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

• Blinks "CHECK TRANS" lamp

• Stores the failure information in failure-memory

• Reverse lockout control inhibit

Conditions of turning “CHECK TRANS” off:

Turns “CHECK TRANS” lamp off when only one of all
switches is ON.

Reversion conditions from fail-safe:

Turns “CHECK TRANS” lamp off when only one of all
switches is ON.

Test description:

The following numbers correspond to the step numbers
on the diagnostic chart.
1. It is judged whether the input signal received from

the neutral start switch by the TCM is proper or not.

5. The power status of the neutral start switch is

checked.

6. The continuity between neutral start switch

terminals and the continuity of the wire connected
to the neutral start switch are checked.

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.

AUTOMATIC TRANSMISSION (AW30-40LE) 7A-43

DTC P0705 (FLASHING CODE 17)

GEAR SELECTOR FAILURE (PRND2L)

Step Action

Value(s)

Yes

1. With the engine "OFF", turn the ignition

"ON".

2. Connect a voltmeter to the each terminals of

the TCM 28 pin connector and TCM 20 pin
connector ground terminal (15 or 19).

3. Measure the voltage shifting the selector

lever to very position.
(Comparison with table 1)

Is the displayed voltage at every position
normal?

See table 1

Go to Step 2

Go to Step 3

1. Clear the TCM memory.
2. Make a running test. (Greater than 30

seconds).

Is DTC P0705 displayed by self-diagnosis?

−

Go to Step 4

The continuity

of wiring is

temporarily

faulty.

Refer to

“Diagnostic

aids”.

Is the displayed voltage at every position
abnormal?

−

Go to Step 5

Go to Step 6

The TCM is faulty or the continuity of wiring is
temporarily faulty.
Refer to "Diagnostic aids".
Was a problem found and corrected?

−

Go to Step 9

−

1. Check if there is any breaking in the fuse and

wire connected to the 10 pin connector
terminal (3) of the neutral start switch.

2. Check the adjusted condition of the neutral

start switch.

3. If no fault is found, replace the neutral start

switch.

Was a problem found and corrected?

−

Go to Step 9

−

1. Disconnect the 10 pin connector of the

neutral start switch.

2. Make a continuity check between each

terminals of the neutral start switch with an
ohmmeter.

Is the continuity at every position normal?

See table 2

Go to Step 7

Go to Step 8

The wiring harness between the TCM and
neutral start switch is open or shorted.
Was a problem found and corrected?

−

Go to Step 9

−

Replace the neutral start switch.
Is the replacement complete?

−

Go to Step 9

−

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 test failed or is the current DTC
displayed?

− Begin

the

diagnosis

again.

Go to Step 1

System OK

7A-44 AUTOMATIC TRANSMISSION (AW30-40LE)

(Table

TCM 20 pin

terminal (-)

TCM 28 pin

terminal (+)

Voltage (V)

8-16: P range

1 or less: Other than P range

8-16: R range

1 or less: Other than R range

8-16: N range

1 or less: Other than N range

8-16: D range

1 or less: Other than D range

8-16: 2 range

1 or less: Other than 2 range

8-16: L range

1 or less: Other than L range

(Table

Terminal

Neutral start switch 10 pin connector

Range

1 4 3 5 2 6 8 7 9

Continuity

Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 298