ISUZU TF SERIES 2004 Workshop Manual

DIAGNOSIS (JR405E) 7A2-139
No. Z11: Abnormal Oil Pressure

Description:

Oil pressure is low or high.

Possible Cause:

Basically, the same cause as "No. C1 - C8: Engine races up (slip) by shift up or shift down" is considered.

In case of oil pressure is low, faulty oil pump is considered.




No. Z12: Reverse Buzzer Does Not Ring

Description:

Reverse buzzer does not ring in R range.

Possible Cause:

Disordered select cable.

Disordered select lever.

Disordered inhibitor switch.

7A2-140 DIAGNOSIS (JR405E)
STALL TEST
CAUTION:
Because A/T may break down, do not perform the stall test continuously.

Procedure
1. Chock the four wheels.
2. Warm up the engine.
3. Apply the parking brake.
4. Step on the foot brake fully.
5. Set the select lever to either D, 3, 2, L or R range.
6. Step on the accelerator pedal fully.
7. When the engine speed becomes constant, record tha
t
value quickly.

Stall Speed
Standard: 2600±150 rpm

Evaluation
1. If the stall speed is higher than standard value in all
ranges.

Low line pressure.

Abraded oil pump.

Faulty operation of low clutch.

Adjustment error of or faulty inhibitor switch.


ATF leaking from oil pump, control valve, or
transmission case.

Fixed pressure regulator valve and pilot valve.
2. If the stall speed is higher than standard value in D, 3, 2
and L ranges.

Slip of low clutch.

Slip of low one-way clutch.
3. If the stall speed is higher than standard value in
R
range.

Slip of low & reverse brake.

Slip of reverse clutch.
4. If the stall speed is lower than standard value in all
ranges.

Slip of one-way clutch (in torque converter).

Faulty engine.

DIAGNOSIS (JR405E) 7A2-141
LINE PRESSURE TEST
Procedure
1. Chock the four wheels.
2. Remove the test plug of the transmission case and fit the oil
pressure gauge.
3. Warm up the engine.
4. Apply the parking brake.
5. Step on the foot brake fully.
6.Set the select lever to either D, 3, 2, L or R range.
7. Record the oil pressure at idling.
8. When stepping over the accelerator pedal fully and the
engine speed becomes constant, record the oil pressure
quickly.

Line Pressure
Standard:
Engine Line Pressure (Kpa)
Speed D, 3, 2 or L Range R Range
Idling 350 - 480 450 - 650
Stall 1,050 - 1,250 1.400 - 1,630

Evaluation
1. If the line pressure is lower than standard value at
idling in all ranges.

Abraded oil pump.

Faulty operation of each solenoid.

Sticking of pressure regulator valve or pilot valve.

Fatigued pressure regulator valve or pilot valve spring.


ATF leaking from oil strainer, oil pump, pressure
regulator valve, torque converter relief valve or pressure
relief valve.
2. If the line pressure is lower than standard value at
idling in D, 3, 2 and L ranges.

ATF leaking from low clutch hydraulic circuit.
3. If the line pressure is lower than standard value at
idling in R range.

ATF leaking from reverse hydraulic circuit.

ATF leaking from low and reverse brake hydraulic
circuit.

7A2-142 DIAGNOSIS (JR405E)
1. Oil Cooler Out
2. R Range Line Pressure Detection Port
(Low & Reverse Brake Pressure Detection Port)
3. D, 3, 2 & L Range Line Pressure Detection Port
(Low Clutch Pressure Detection Port)
4. Oil Cooler In

4. If the line pressure is lower than standard value at
idling in L and R ranges.


ATF leaking from low and reverse brake hydraulic
circuit.
5. If the line pressure is higher than standard value at
idling in all ranges.

Throttle opening signal reception error.

Faulty oil temperature sensor.

Faulty operation of low clutch solenoid.

Sticking pilot valve.

Sticking pressure regulator valve or plug.
6. If the line pressure is lower than standard value at stall
speed in all ranges.

Throttle opening signal reception error.

Faulty operation of line pressure solenoid.

Faulty operation of low clutch solenoid.

Sticking pilot valve.

Sticking pressure regulator valve or plug.

DIAGNOSIS (JR405E) 7A2-143
TIME LAG TEST
Procedure
1. Chock the four wheels.
2. Warm up the engine.
3. Apply the parking brake.
4. Step on the foot brake fully.
5. Set the select lever from N to D or N to R range.
6. Record the time from when moving the select button until
feeling shock.

Time Lag
Standard:
N to D Range: Below 0.7 Seconds
N to R Range: Below 1.2 Seconds

Evaluation
1. If the time lag is out of standard value when shifting N
to D range.

Forward range line pressure is low.

Slip of low clutch.

Slip of low one-way clutch.

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

Faulty low clutch duty solenoid operation.

Shortage or faulty quality of ATF.
2. If the time lag is out of standard value when shifting N
to R range.

Reverse range line pressure is low.

Slip of low & reverse brake.

Slip of reverse clutch.

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

Faulty low & reverse brake duty solenoid operation.

Shortage or faulty quality of ATF.

7A2-144 DIAGNOSIS (JR405E)
TEST DRIVE




NOTE:
Perform the test at normal operation ATF temperature 50 -
80




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

1. D range test in Normal and Power shift pattern.
1) Shift into the D range and hold the accelerator pedal
constant at the 50% and 100% throttle angle.
2) 1-2, 2-3, 3-4 and lock-up, up-shift should take place, and
shift points should confirm to those shown in the
diagram.
3) Also check to see that downshift is made from 4-3, 3-2
and 2-1 down-shift point is within the limits shown in the
diagram.
2. 3 range test in Normal and Power shift pattern.
1) Shift into the 3 range and hold the accelerator pedal
constant at the 50% and 100% throttle angle.
2) 1-2, 2-3 and lock-up, up-shift should take place, and
shift points should confirm to those shown in the
diagram.
3) While running in the 3 rages, does not up-shift 3-4.
4) Also check to see that down-shift is made from 4-3, 3-2
and 2-1 down-shift point is within the limits shown in the
diagram.
3. 2 range test in Normal shift pattern.
1) Shift into the 2 range and hold the accelerator pedal
constant at the 50% and 100% throttle angle.
2) 1-2 and up-shift should take place, and shift points
should confirm to those shown in the diagram.
3) While running in the 2 rages, does not up-shift 2-3 or 3-
4, and lock-up does not operate.
4) Also check to see that down-shift is made from 4-3, 3-2
and 2-1 down-shift point is within the limits shown in the
diagram.


4. L range test in Normal shift pattern.
1) While running in the L rages, does not up-shift 1-2, 2-3
or 3-4, and lock-up does not operate.
2) Also check to see that down-shift is made from 4-3, 3-2
and 2-1 down-shift point is within the limits shown in the
diagram.

DIAGNOSIS (JR405E) 7A2-145

5. R range test.
1) Shift into the R range and while starting at full throttle,
check for slipping.
6.P range test.
1) Stop the vehicle on a grade and after shifting into the P
range, release the parking brake. Then check to see tha
t
the parking lock pawl holds the vehicle in place.


Select
Lever
Position
Gear
Position
Gear
Shift
P










R Reverse





N










D 1st
2nd
3rd
4th
3 1st
2nd
3rd
4th(*1)
2 1st
2nd
3rd(*1)
4th(*1)
L 1st
2nd(*1)
3rd(*1)
4th(*1)
Evaluation
1. If there is no 1 to 2 up-shift.

2-4 brake malfunction.

2-4 brake hydraulic circuit failed.

2-4 brake duty solenoid stick.
Refer to symptom diagnosis "No. D1: Faulty Gea
r
Shifting" or DTC section "Gear Ratio Error".

2. If there is no 2 to 3 up-shift.

High clutch malfunction.

High clutch hydraulic circuit failed.

High clutch duty solenoid stick.
Refer to symptom diagnosis "No. D1: Faulty Gea
r
Shifting" or DTC section "Gear Ratio Error".

3. If there is no 2 to 4 (O/D) up-shift.

2-4 brake malfunction.

2-4 brake hydraulic circuit failed.

2-4 brake duty solenoid stick.
Refer to symptom diagnosis "No. D1: Faulty Gea
r
Shifting" or DTC section "Gear Ratio Error".

4. If there is no lock-up in 2, 3 and 4.

Lock-up piston malfunction.

Lock-up hydraulic circuit failed.

Lock-up duty solenoid stick.
Refer to symptom diagnosis "No. I1: No Lock-up"o
r
DTC section "Lock-up Duty Solenoid Failure".


*1: Transmission is shifted at high speed to
prevent engine over-run.

7A2-146 DIAGNOSIS (JR405E)

5. If there is no reverse.

Reverse clutch malfunction.

Reverse clutch hydraulic circuit failed.

Low & reverse brake hydraulic circuit failed.

Low & reverse brake duty solenoid stick.
Refer to symptom diagnosis "No. A2: Vehicle Dose Not
Run in R Range" or DTC section "Low & Reverse
Brake Duty Solenoid Failure".
6. If there is no parking.

Parking pawl malfunction.
Refer to symptom diagnosis "No. G1: Vehicle Moves in
P Range or Parking Gear in Not Disengaged othe
r
than P Range".

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 propeller shaft, differential, the torque
converter, etc. Or insufficient bending, rigidity, etc. in the
powertran.

DIAGNOSIS (JR405E) 7A2-147
SHIFT POINT CHART
D Range
Normal Mode Power Mode 4L Mode
Gear Throttle
Position
Velocity (km/h) Output Shaft
Speed (rpm)
Velocity (km/h) Output Shaft
Speed (rpm)
Velocity (km/h) Output Shaft
Speed (rpm)
1
2 50%25-3127-33 93029-3531-37105428-34 30-361023
100%36-4237-43 127136-4238-44127132-38 34-401147
2
3 50%46-5249-55 161255-6158-64189152-58 55-611798
100%75-8179-85 254275-8179-85254267-73 71-772294
3
4 50%80-8684-90 269783-8988-94282180-86 84-902697
100%118-124125-131 3967118-124125-1313967107-113 113-1193595
4
3 0%27-3329-35 99227-3329-3599227-33 29-35992
50%52-5855-61 179870-7674-80238767-73 71-772294
100%102-108108-114 3440102-108108-114344093-99 98-1043130
3
2 0%6-126-12 2796-126-122796-12 6-12279
50%28-3430-36 102344-5047-53155043-49 46-521488
100%61-6764-70 207761-6764-70207756-62 59-651922
2
1 0%6-126-12 2796-126-122796-12 6-12279
50%9-1510-16 40318-2419-2568217-23 18-24651
100%27-3329-35 99227-3329-3599225-31 27-36930
Axle Gear Ratio 4.300 4.300 4.300 4.300 4.300 4.300
Tire Radius 0.349 0.368 0.349 0.368 0.349 0.368

3 Range
Normal Mode Power Mode 4L Mode
Gear Throttle
Position
Velocity (km/h) Output Shaft
Speed (rpm)
Velocity (km/h) Output Shaft
Speed (rpm)
Velocity (km/h) Output Shaft
Speed (rpm)
1
2 50%25-3127-33 93029-3531-37105428-34 30-361023
100%36-4238-44 127136-4238-44127132-38 34-401147
2
3 50%46-5249-55 161255-6158-64189152-58 55-611798
100%75-8179-85 254275-8179-85254267-73 71-772294
4
3 0%118-124125-131 3967118-124125-1313967107-113 113-1193595
50%118-124125-131 3967118-124125-1313967107-113 113-1193595
100%118-124125-131 3967118-124125-1313967107-113 113-1193595
3
2 0%6-126-12 2796-126-122796-12 6-12279
50%28-3430-36 102344-5047-53155043-49 45-511488
100%61-6764-70 207761-6764-70207757-63 59-651922
2
1 0%6-126-12 2796-126-122796-12 6-12279
50%9-1510-16 40318-2419-2568217-23 18-24651
100%27-3329-35 99227-3329-3599225-31 27-33930
Axle Gear Ratio 4.300 4.300 4.300 4.300 4.300 4.300
Tire Radius 0.349 0.368 0.349 0.368 0.349 0.368

7A2-148 DIAGNOSIS (JR405E)

2 Range
Normal Mode 4L Mode
Gear Throttle
Position
Velocity (km/h) Output Shaft
Speed (rpm)
Velocity (km/h) Output Shaft
Speed (rpm)
1
2 50%25 -31 27-3393028-3430-361023
100%36 -42 38-44127132-3834-401147
4
3 0%119 -125 125-1313967107-113113-1193595
50%119 -125 125-1313967107-113113-1193595
100%119 -125 125-1313967107-113113-1193595
3
2 0%75 -81 79-85254267-7371-772294
50%75 -81 79-85254267-7371-772294
100%75 -81 79-85254267-7371-772294
2
1 0%6 -12 6-122796-126-12279
50%9 -15 10-1640317-2318-24651
100%27 -33 29-3599225-3127-33930
Axle Gear Ratio 4.300 4.300 4.300 4.300
Tire Radius 0.349 0.368 0.349 0.368

L Range
Normal Mode 4L Mode
Gear Throttle
Position
Velocity (km/h) Output Shaft
Speed (rpm)
Velocity (km/h) Output Shaft
Speed (rpm)
4
3 0%118-124125-1313967107-113113-1193595
50%118-124125-1313967107-113113-1193595
100%118-124125-1313967107-113113-1193595
3
2 0%75-8179-85254267-7371-772294
50%75-8179-85254267-7371-772294
100%75-8179-85254267-7371-772294
2
1 0%36-4238-44127132-3834-401147
50%36-4238-44127132-3834-401147
100%36-4238-44127132-3834-401147
Axle Gear Ratio 4.300 4.300 4.300 4.300
Tire Radius 0.349 0.368 0.349 0.368