Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual — part 1870

7A2-96 DIAGNOSIS

No. A3: Vehicle Does Not Run in D, 3, 2 and L Range

Description:

•

Vehicle does not run in D, 3, 2 and L range only.

•

It runs correctly in R ranges.

Diagnosis Hints:

•

Some trouble in the AT main unit is supposed (since the vehicle can run even if the TCM is defective). However,

since the trouble of the main unit may be originated from the sensor system or output system, these systems

should be also checked to prevent reproduce of the trouble.

Possible Cause:

•

Slip of clutch (low clutch and low one-way clutch).

If slip of clutch is caused, a DTC (gear ratio error) is stored.

•

Shortage or faulty quality of ATF.

•

Dropped line pressure.

•

Trouble in control valve body (faulty operation, sticking, clogged oil passage).

•

Disordered select cable (select indicator light indicates D, 3, 2 and L but the hydraulic system is not in the D, 3, 2

and L range).

•

Faulty torque generated.

•

Trouble in the torque converter (faulty operation, sticking), insufficient engine output.

•

Malfunction of parking mechanism.

Step

Action

Yes

No

1

Dislocation or disordered of select lever.
Does the vehicle move when the brake is released in a
position other than the P range and the vehicle is pushed?

Go to Step 2

Adjust the select cable.

2

Are any DTCs stored?

Go to DTC Chart

Go to Step 3

3

Are the quantity, contamination and smell normal?

If the ATF level is low,

replenish up to the

specified level.

Go to Step 4

If ATF is extremely

black and

contaminated and

smells burnt, slip of the

clutch is supposed.

Overhaul the AT unit.

4

Is the stall revolution correct in D, 3, 2 and L range? Refer
the STALL TEST section in this manual.

Go to Step 5

Repair the defect or

replace.

5

Is the line pressure correct? Refer the LINE PRESSURE
TEST section in this manual.

Trouble in the AT

assembly or control

valve.

Repair the defect or

replace.

DIAGNOSIS 7A2-97

No. B1: Vehicle Runs in N Range

Description:

•

Creep appears in N range.

•

Vehicle moves unless the brake pedal is stepped on in N range.

Diagnosis Hints:

•

Basically a trouble in the AT main unit. However, some trouble in the sensor system or output system may have

some influence on the trouble in the main unit and therefore these systems should be also checked to prevent

reproduce of the trouble.

Possible Cause:

•

Seized clutch (low clutch, low one-way clutch, reverse clutch, low & reverse brake).

•

Trouble in the control valve (faulty operation, sticking, clogged oil passage).

•

Dislocated select lever (the select indicator light indicates the N range but the hydraulic system is in the D, 3, 2

or L range).

Step

Action

Yes

No

1

Dislocation or disordered of select lever.
Does the vehicle move when the brake is released in a
position other than the P range and the vehicle is pushed?

Go to Step 2

Adjust the select cable.

2

Are any DTCs stored?

Go to DTC Chart

Go to Step 3

3

Are the quantity, contamination and smell normal?

If the ATF level is low,

replenish up to the

specified level.

Trouble in the AT

assembly or control

valve.

If ATF is extremely

black and

contaminated and

smells burnt, slip of the

clutch is supposed.

Overhaul the AT unit.

7A2-98 DIAGNOSIS

No. B2: Poor Acceleration at Starting

Description:

•

Starting acceleration is poor.

Diagnosis Hints:

•

In addition to the low engine output, faulty gear shifting of AT or fixing at the 3rd position may be possible.

Therefore, in case of such a trouble that "maximum speed is low, and acceleration is poor", it should be cleared

up whether the trouble is originated from the engine system of AT system by a running test, inspection of stall

revolution, etc.

Possible Cause:

•

Clogged air cleaner, out of injection timing, dropped compression pressure, etc.

•

Fixing at 3rd position (fail-safe activated).

Since the gear is fixed at the 3rd position because of the fail-safe function, a trouble that "Maximum

speed is low, and acceleration is poor" is resulted. In this case, the DTC is memorized.

When TCM stops operation because of faulty TCM ground, the gear is fixed at the 3rd position because

of a mechanical reason. In this case, no DTC is memorized.

•

Disordered inhibitor switch.

•

Incorrect properties of throttle opening signal (serial communication) of throttle position sensor.

Throttle opening signal (serial communication) of the throttle position sensor does not change in

proportion to the throttle opening. In this case, fixing at the high or low gear results in such a trouble

that "Maximum Speed is Low and Acceleration is Poor".

•

Slip of clutch (low clutch, high clutch).

•

If slip of clutch is caused, a DTC (gear ratio error) is stored.

•

Dropped line pressure.

•

Trouble in the torque converter system (faulty operation).

Step

Action

Yes

No

1

Test Drive.
Is the gear smoothly shifted in the order of 1st to 2nd, 2nd to 3rd,
3rd to 4th gear and lock up?

Clogged air cleaner,

out of injection

timing, dropped

compression

pressure, etc.

Go to Step 2

2

Gear ratio trouble diagnosis.
Travel in the following sequence for about 7 seconds or more in
each range: Start in the L range (1st) to 2 range (2nd) to 3 range
(3rd) to D range (4th) (to detect the gear ratio trouble exactly, this
process should be carried out)

Go to Step 3

Go to Step 3

3

Are any DTCs stored?

Go to DTC Chart

Go to Step 4

DIAGNOSIS 7A2-99

Step

Action

Yes

No

4

Are the quantity, contamination and smell normal?

If the ATF level is

low, replenish up to

the specified level.

Go to Step 5

If ATF is extremely

black and

contaminated and

smells burnt, slip of

the clutch is

supposed.

Overhaul the AT

unit.

5

Inspection of inhibitor switch using a Tech 2 or circuit tester.
When the select lever is operated, is the data display in the Tech 2
correct or voltage at each range correct?

Inhibitor SW

TCM

A2 (P)

A17 (3)

B2 (2)

B10 (N)

B11 (D)

B19 (R)

B21 (L)

C95

(2)

(10)

(11)

(19)

(21)

YEL/VIO

RED/BLK

BLU

BLK/GRN

Starter Relay

C94

(2)

(3)

B

H22

(1)

(6)

(4)

(7)

(5)

(2)

P

2

R

N

D

3

L

Start SW

PNK/BLU

E51

(2)

(4)

(8)

(5)

(1)

(9)

(6)

(3)

(10)

(7)

(38)

(15)

(3)

(37)

H4

PNK/BLK

RED/YEL

YEL/VIO

BLK/GRN

PNK/BLK

RED/BLK

BLU

RED/YEL

PNK/BLU

BLK/WHT

BLK

BLK

BLK/WHT

Key Switch

WHT

WHT

Immobiliser Control Unit

TCM terminal

Range

A2

B19

B10

B11

B17

B2

B21

P

Battery
voltage

-

-

-

-

-

-

R

-

Battery

voltage

-

-

-

-

-

N

-

-

Battery
voltage

-

-

-

-

D

-

-

-

Battery
voltage

-

-

-

3

-

-

-

-

Battery
voltage

-

-

2

-

-

-

-

-

Battery

voltage

-

L

-

-

-

-

-

-

Battery
voltage

Go to Step 6

Adjust the inhibitor

switch.