Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual — part 1771

DIAGNOSIS 7A2-135

No. G4: Large Noise During Idling with the Vehicle in Stop State

Description:

•

The transmission is noisy during the idling speed in all ranges.

Diagnosis Hints:

•

Causes such as solenoid operating sound or faulty oil pump are considered.

•

Distinguishing to some extent is possible by stopping the solenoid operation temporarily, checking the correlation

for the former case and, changing the line pressure and confirming the correlation with noise.

•

As a matter of course, noise may be generated around the engine, for instance, other than the AT and should be

checked carefully.

Note:

When the noise is generated only at the time of gear shift, it may be the sound of flowing ATF or gear

noise. If the sound varies depending on the gear speed to be shifted, it may be the gear noise generated

from the planetary gear and its related components. If the sound varies depending on the vehicle

speed, it may be the gear noise of the output system, and if varying depending on the engine speed, it

may be the gear noise of the input system or faulty torque converter.

In either case, sound may be "noise" depending on the origin and resonance object. When the object

generating the sound (resonance object) and the sound source (vibration source) are different,

investigation of the cause may be difficult.

No. H1: Judder Occurs at the Lock-up

Diagnosis Hints:

･The vehicle body judders at lock-up.

Diagnosis Hints:

･Slip due to burning of the lockup piston or insufficient fastening due to dropped working pressure are considered.

Trouble diagnosis flow is basically the same as "No. I1: No lock-up".

Note:

When the lock-up piston has burnt, foreign material mixed in the oil cooler is considered. In such a

case, inspect the oil cooler circuit for clogging of the oil cooler.

No. H2: Large Lock-up Shock

No. H3: Lock-up Point is High or Low

Description:

•

Large shock is felt at lock-up.

•

Lock-up point is excessive high or low.

Diagnosis Hints:

•

Out of properties of input sensor or faulty lock-up piston pressure system are considered.

•

Trouble diagnosis flow is basically the same as "No. I1: No lock-up".

7A2-136 DIAGNOSIS

No. I1: No Lock-up

Description:

•

Lockup is not performed in spite of the lock-up area.

Diagnosis:

•

Lockup is not performed in spite of the lock-up area.

•

Monitor the signal to the lock-up solenoid while carrying out a running test.

•

When the output signal to the lock-up solenoid is correctly sent causing no lock-up, clogged lock-up solenoid oil

passage or malfunction of the lock-up piston may be considered.

•

Even the lock-up area, the output signal to the lock-up solenoid is not sent, fault of the ATF thermo sensor

controlling the lockup is considered. (Lock-up is not operated at ATF temperature less than 11

°C or more than

128

°

C.)

Note:

When the lock-up piston has burnt, foreign material mixed in the oil cooler is considered. In such a

case, inspect the oil cooler circuit for clogging of the oil cooler

Possible Cause:

•

ATF thermo sensor detects low oil temperature (Lock-up is prohibited temperature less than 10

°

C.).

•

Clogged oil passage of lock-up duty solenoid.

•

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

Step

Action

Yes

No

1

Are any DTCs stored?

Go to DTC Chart

Go to Step 2

2

Are the quantity, contamination and smell normal?

If the ATF level is

low, replenish up to

the specified level.

Go to Step 3

If ATF is extremely

black and

contaminated and

smells burnt, slip of

the clutch is

supposed.

Overhaul the AT

unit.

DIAGNOSIS 7A2-137

Step

Action

Yes

No

3

Inspection of electrical or mechanical fault
When the ATF oil temperature is above 20

°

C and the vehicle

speed is 80km/h, is ON signal issued to the lock-up solenoid
using the Tech 2 or circuit tester?

Control Valve

TCM

B17

B23

BLK

Lock-up Solenoid

Terminal

Assembly

VIO

Line Pressure Solenoid

E54

(4)

(6)

H23

(14)

(6)

C95

(17)

(23)

BLK

VIO

TCM terminal

Lock-up

B17

At lock-up

Approx. 7.2 V (AC range)

At unlock-up

Approx. 4.0 V (AC range)

Clogged oil

passage of lock-up

solenoid or faulty

operation of lock-

up piston.

Go to Step 4

4

Inspection of ATF oil thermo sensor.
Is the ATF oil temperature sensor terminal voltage correct?
After running using the Tech 2 data display function, is the ATF
temperature higher than 10

°

C?

ATF

Temp.

Sensor

TCM

B4 (+)

B14 (-)

H23

(8)

(3)

C95

(4)

(14)

BLU

Terminal

Assembly

BLU/BLK

E54

(2)

(8)

BLU

BLU/BLK

T C M te r m in a l

Te m p e r a tu r e

B 4

( O u tp u t v o lta g e )

2 0

1 .5 5

4 0

1 .0 8

6 0

0 .7

Monitor the electric

system input

sensor signal and

find a signal

causing no lockup.

Repair the defect or

replace.

7A2-138 DIAGNOSIS

No. J1: Oil Leaks from Breather

Description:

•

Oil leaks from breather.

Possible Cause:

•

ATF quantity is excessively.

No. J2: Oil Leaks Between Engine and Converter Housing
No. J3: Oil Leaks Between Main Case and Converter Housing
No. J4: Oil Leaks Between Main Case and Rear Housing
No. J5: Oil Leaks from Oil Pan
No. J6: Oil Leaks from Manual Shaft Oil Seal
No. J7: Oil Leaks from Oil Cooler Pipe Joint

Description:

•

Oil leaks between engine and converter housing.

•

Oil leaks between converter housing and main case.

•

Oil leaks between main case and rear housing.

•

Oil leaks from oil pan.

•

Oil leaks from manual shaft oil seal.

•

Oil leaks from oil cooler pipe joint.

Possible Cause:

•

Faulty oil seal or sealing of contact surface is considered.

No. Z1: Transmission Overheat

Description:

•

You smell the transmission burning.

•

The transmission smokes.

Possible Cause:

•

Slip

of

clutch.

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

•

Clogged oil cooler (foreign substance mixed)

•

ATF stirred excessively (too much ATF).

•

Faulty torque converter operating pressure.

•

Faulty lock-up piston.