Nissan Frontier D22. Manual - part 15

TROUBLE DIAGNOSIS — BASIC INSPECTION

AT-29

[RL4R01A]

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Line Pressure Test

ECS007IT

LINE PRESSURE TEST PORTS

Location of line pressure test ports are shown in illustration.

●

Line pressure plugs are hexagon-headed bolts.

●

Always replace line pressure plugs as they are self-sealing
bolts.

LINE PRESSURE TEST PROCEDURE

1.

Check A/T fluid and engine oil levels. If necessary, add fluid and
oil.

2.

Drive vehicle for approx. 10 minutes or until fluid and oil reach
operating temperature.

3.

Install pressure gauge to line pressure port.

— D, 2 and 1 positions —
— R position —

SAT176G

ATF operating temperature

: 50 - 80

°C (122 - 176°F)

SAT647B

AAT809

AAT810

AT-30

[RL4R01A]

TROUBLE DIAGNOSIS — BASIC INSPECTION

4.

Set parking brake and block wheels.

●

Continue to depress brake pedal fully while performing
line pressure test at stall speed.

5.

Start engine and measure line pressure at idle and stall speed.

●

When measuring line pressure at stall speed, follow the
stall test procedure.

JUDGEMENT OF LINE PRESSURE TEST

SAT513G

Line pressure

: Refer to 

AT-150, "Line Pressure"

 .

SAT494G

Judgement

Suspected parts

At idle

Line pressure is low in all positions.

●

Oil pump wear

●

Control piston damage

●

Pressure regulator valve or plug sticking

●

Spring for pressure regulator valve damaged

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Fluid pressure leakage between oil strainer and pres-
sure regulator valve

●

Clogged strainer

Line pressure is low in particular position.

●

Fluid pressure leakage between manual valve and par-
ticular clutch.

●

For example, line pressure is:
— Low in R and 1 positions, but
— Normal in D and 2 positions.
Therefore, fluid leakage exists at or around low & 
reverse brake circuit.
Refer to 

AT-152, "Clutch and Brakes"

 .

Line pressure is high.

●

Maladjustment of throttle position sensor

●

Fluid temperature sensor damaged

●

Line pressure solenoid valve sticking

●

Short circuit of line pressure solenoid valve circuit

●

Pressure modifier valve sticking

●

Pressure regulator valve or plug sticking

At stall speed

Line pressure is low.

●

Maladjustment of throttle position sensor

●

Control piston damaged

●

Line pressure solenoid valve sticking

●

Short circuit of line pressure solenoid valve circuit

●

Pressure regulator valve or plug sticking

●

Pressure modifier valve sticking

●

Pilot valve sticking

TROUBLE DIAGNOSIS — BASIC INSPECTION

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Governor Pressure Testing

1.

Check A/T and engine fluid levels. If necessary, add fluid.

2.

Drive vehicle for approx. 10 minutes or until engine oil and ATF
reach operating temperature.

3.

Install pressure gauge to governor pressure port.

4.

Jack up front and rear wheels.

5.

Set selector lever in D position and gradually depress accelera-
tor pedal.

●

Be careful of rotating wheels.

●

Governor pressure is not generated when vehicle is
stopped.

●

Governor pressure rises gradually in response to vehicle
speed.

If not, check governor valve assembly. Refer to 

AT-101, "GOVER-

NOR VALVE ASSEMBLY"

 .

Road Test

ECS007IU

Perform road tests using symptom chart. Refer to 

AT-33, "Symptom Chart"

 .

P POSITION

1.

Place selector lever in P position and start the engine. Stop the engine and repeat the procedure in all
positions, including N position.

2.

Stop vehicle on a slight upgrade and place selector lever in P position. Release parking brake to make
sure vehicle remains locked.

R POSITION

1.

Manually move selector lever from P or R, and note shift quality.

2.

Drive vehicle in reverse long enough to detect slippage or other abnormalities.

N POSITION

1.

Manually move selector lever from R and D to N and note shift quality.

2.

Release parking brake with selector lever in N position. Lightly depress accelerator pedal to make sure
vehicle does not move. (When vehicle is new or soon after clutches have been replaced, vehicle may
move slightly. This is not a problem.)

ATF operating temperature

: 50 - 80

°C (122 - 176°F)

AAT682A

AAT875

Governor pressure

: Refer to 

AT-150, "Governor 

Pressure"

 .

AAT876

AT-32

[RL4R01A]

TROUBLE DIAGNOSIS — BASIC INSPECTION

D POSITION

1.

Manually shift selector lever from N to D position, and note shift
quality.

2.

Using the shift schedule as a reference, drive vehicle in D posi-
tion. Record, on Symptom Chart, respective vehicle speeds at
which up-shifting and down-shifting occur. These speeds are to
be read at three different throttle positions light, half and full.
Also determine the timing at which shocks are encountered dur-
ing shifting and which clutches are engaged.

3.

Determine whether lock-up properly occurs while driving vehicle
in proper gear position and at proper speeds.

4.

Check to determine if shifting to overdrive gear cannot be made
while overdrive control switch is OFF.

5.

Drive vehicle at 65 to 80 km/h (40 to 50 MPH) with half to light
throttle position (D

3

  position). Fully depress accelerator pedal to

make sure transmission downshifts from 3rd to 2nd gear.

6.

Drive vehicle at 35 to 45 km/h (22 to 28 MPH) with half to light
throttle position (D

2

  position). Fully depress accelerator pedal to

make sure transmission downshifts from 2nd to 1st gear.

2 POSITION

1.

Shift to 2 position and make sure vehicle starts in 1st gear.

2.

Increase vehicle speed to make sure transmission upshifts from 1st to 2nd gear.

3.

Further increase vehicle speed. Make sure transmission does not upshift to 3rd gear.

4.

Drive vehicle at 35 to 45 km/h (22 to 28 MPH) with throttle at half to light position (2

2

    position).  Fully

depress accelerator pedal to make sure transmission downshifts from 2nd to 1st gear.

5.

Drive vehicle at idle in 2 position to make sure that transmission downshifts to 1st gear.

6.

Move selector lever to D position and drive vehicle at 40 to 50 km/h (25 to 31 MPH). Then, move selector
lever to 2 position to make sure transmission downshifts to 2nd gear.

1 POSITION

1.

Place selector lever in 1 position and accelerate. Make sure transmission does not shift from 1st to 2nd
gear although vehicle speed increases.

2.

While driving vehicle in 1 position, release accelerator pedal to make sure that engine compression acts
as a brake.

3.

Place selector lever in D or 2 position and drive vehicle at 20 to 30 km/h (12 to 19 MPH). Then move
selector lever to 1 position to make sure transmission downshifts to 1st gear.

AAT164A

AAT165A