Isuzu Trooper (1998-2002 year). Manual - part 717

AUTOMATIC TRANSMISSION (AW30-40LE)

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HYDRAULIC TEST

PREPARATION

1) Warm up the transmission fluid.

2) Remove the transmission case test plug and mount the

hydraulic pressure gauge.
Oil pressure gauge: 5-8840-0093-0

NOTE:  
Perform the test at normal operating fluid temperature (50
– 80

°

C or 122 – 176

°

F).

MEASURE LINE PRESSURE

1) Fully apply the parking brake and chock the four wheels.

2) Start the engine and check idling rpm.

3) Shift into "D" range, step down strongly on the brake pedal

with your left foot and, while manipulating the accelerator
pedal with the right foot, measure the line pressures at the
engine speeds specified in the table.

4) In the same manner, perform the test in "R" range.

EVALUATION

1) If the measured values at all ranges are higher than

specified.

• Pressure control solenoid defective.

• Primary regulator valve defective.

2) If the measured values at all ranges are lower than

specified.

• Primary regulator valve defective.

• Oil pump defective.

• Pressure control solenoid defective.

3) If pressure is low in "D" range only:

• "D" range circuit fluid leakage.

4) If pressure is low in "R" range only:

• "R" range circuit fluid leakage.

Engine 

speed

Line pressure kPa (kg/cm

2

/psi)

"D" range

"R" range

Idling

358 – 417

(3.6–4.3 / 51–61)

588 – 686

(6.0–7.0 / 85–100)

Stall

1,176 – 1,323

(12.0–13.5 / 171–192)

1,607 – 1,940

(16.4–19.8 / 233–282)

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ROAD TEST

NOTE: 

Perform the test at normal operation fluid temperature (50

– 80

°

C or 122 – 176

°

F).

"D" RANGE TEST IN "NORMAL", AND "POWER"
PATTERN RANGES

Shift into the "D" range and hold the accelerator pedal constant
at the 50% and 100% throttle valve opening positions.
Push in one of the pattern selector buttons and check the
following:

1) 1-2, 2-3, 3-OD and lock-up, up-shifts should take place,

and shift points should conform to those shown in the
automatic shift diagram.

NOTE:  
Drive the vehicle on level ground so as not to change to up
and down hill control.

EVALUATION

(1) If there is no 1 

→

 2 up-shift:

• No. 2 solenoid is stuck

• 1-2 shift valve is stuck

(2) If there is no 2 

→

 3 up-shift:

• No. 1 solenoid is stuck

• 2-3 shift valve is stuck

(3) If there is no 3 

→

 OD up-shift (throttle valve opening 1/2):

• No. 2 solenoid is stuck

• 3-4 shift valve is stuck

(4) If the shift point is defective:

Refer to

 "TROUBLESHOOTING CHART" in this section. 

(5) If the lock-up is defective:

Refer to

 "TROUBLESHOOTING CHART" in this section. 

2) In the same manner, check the shock and slip at the 1 

→

 2,

2 

→

 3 and 3 

→

 OD up-shifts.

EVALUATION

If the shock is excessive:
Refer to

 "TROUBLESHOOTING CHART" in this section. 

AUTOMATIC TRANSMISSION (AW30-40LE)

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3) Run at "D" range lock-up or OD gear and check for

abnormal noise and vibration.

NOTE:  
The check for the cause of abnormal noise and vibration
must be made with extreme care as it could also be due to
loss of balance in the propeller shaft, differential, the
torque converter, etc. or insufficient bending, rigidity, etc.
in the power train.

4) While running in "D" range, 2nd, 3rd gears and OD, check

to see that the possible kick-down vehicle speed limits for 2

→

 1, 3 

→

 1, 3 

→

 2, OD 

→

 3 and OD 

→

 2 kick-downs

conform to those indicated on the automatic shift diagram.

5) Check for abnormal shock and slip at kick-down.

6) While running in "D" range, OD gear or "lock-up", shift to

"2" and "L" ranges and check the engine braking effect at
each of these ranges.

7) Also check to see that downshift is made from 3 

→

 2 or

from OD to 3 and then to 2 immediately and that 2 

→

  1

downshift point is within the limits shown in the diagram
when tested by releasing the accelerator pedal and shifting
into position of "L" while driving in the third gear or in
overdrive.

EVALUATION

(1) If there is no engine braking effect in the "2" range:

• Second coast (No. 1) brake is defective.

(2) If there is no engine braking effect in the "L" range:

• First and reverse (No. 3) brake is defective

(3) Also check to see that downshift is made from 3 

→

 2 or

from OD to 3 and then to 2 immediately and that 2 

→

  1

downshift point is within the limits shown in the diagram
when tested by releasing the accelerator pedal and shifting
into "L" position while driving in the third gear or in
overdrive.

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AUTOMATIC TRANSMISSION (AW30-40LE)

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"2" RANGE TEST

Shift into "2" range and, while driving with the accelerator pedal
held constantly at the specified point (throttle valve opening
50% and 100%), push in one of the pattern selectors (only for
4x4) and check on the following points.

1) At each of the above throttle openings, check to see that

the 1 

→

 2 up-shift takes place and that the shift points

conform to those shown on the automatic shift diagram.

NOTE:  
There is no OD and no lock-up in the "2" range.

2) While running in the "2" range and 2nd gear, release the

accelerator pedal and check the engine's braking effect.

3) Check for 2 

→

 1 down-shift and abnormal noise at

acceleration and deceleration, and for shock at upshift and
down-shift.

"L" RANGE TEST

1) While running above 90 km/h (56 mph) in the "D" range,

release your foot from the accelerator pedal and shift into
the "L" range.
Then check to see that the 2 

→

 1 and 3 

→

 2 down-shift

occurs at the specified point shown on the automatic shift
diagram.

2) While running in the "L" range, check to see that there is no

up-shift to 2nd gear.

3) While running in the "L" range, release the accelerator

pedal and check the engine braking effect.

4) Check for abnormal noise during acceleration and

deceleration.

"R" RANGE TEST

Shift into the "R" range and, while starting at full throttle, check
for slipping.

"P" RANGE TEST

Stop the vehicle on a grade (more than 9%) and after shifting
into the "P" range, release the parking brake. Then check to
see that the parking lock pawl holds the vehicle in place.