parking brake ISUZU TF SERIES 2004 Repair Manual

DIAGNOSIS (JR405E) 7A2-93
No. A1: Vehicle Does Not Run in D, 3, 2, L and R Range

Description:

Vehicle does not run though the accelerator pedal is stepped on.

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, low one-way clutch, reverse clutch, low & reverse brake).
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, L or R but the hydraulic system is not in the D, 3,
2, L, or R 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 all 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.

7A2-94 DIAGNOSIS (JR405E)
No. A2: Vehicle Does Not Run in R Range

Description:

Vehicle does not run in R range only.

It runs correctly in D, 3, 2, and L 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 (reverse clutch, low & reverse brake).
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 R but the hydraulic system is not in the R 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 R 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 (JR405E) 7A2-95
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 (JR405E) 7A2-107
No. B10: Brake is Applied in R Range

Description:

Brake is applied suddenly in R 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, high clutch, 2-4 brake).

Shortage or faulty quality of ATF.

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

Disordered select cable (select indicator light indicates R but the hydraulic system is not in the R range).

Malfunction of parking mechanism.


No. B11: Insufficient Starting or Shaking in D Range

Description:

Insufficient starting or shaking in D range.

Possible Cause:

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


No. B12: Noise or Vibration is Generated at Starting

Description:

Noise or vibration is generated in the vicinity of AT at starting.

Diagnosis Hints:

Cause other than AT can be also considered. It is effective means to reproduce a running condition using a lift
up, chassis dynamo, etc. to investigate the origin (generating condition) of noise and vibration.
Caution:
Lifting up some unit to test it accompanies danger. Provide safety measures as far as possible and
carry out the test with sufficient care.

Possible Cause:
Following sources of noise or vibration other than the AT can be considered.

Noise from differential gears.

Noise from propeller shaft.

The bearing support in the middle of the propeller shaft has fatigued, and the bend angle of the propeller shaft
has changed, causing vibration at the time of start.

Unbalanced and poor uniformity of tires cause vibration.

DIAGNOSIS (JR405E) 7A2-131
No. F5: Engine Stalls Before Vehicle Stops from Running

Description:

The engine stalls simultaneously with the vehicle stop when the brake pedal is stepped on to stop the vehicle
during the running.

Possible Cause:

Trouble on the engine system side (fuel injection control, engine speed control, etc.) is considered.

Refer to "No. B5: Engine stalls when selecting from N range to R, D, 3, 2 or L range".





No. G1: Vehicle Moves in P Range or Parking Gear is Not
Disengaged other than P Range

Description:

Vehicle moves though it stops at a slope and P range is selected.

The engine stalls and vehicle does not move though other than P range is selected and the accelerator pedal is
stepped on.

Possible Cause:

Trouble of the parking mechanism (noise or shock may result).

Disordered selector cable (only when traveling in the P range).

If the vehicle moves in the N range, follow the procedure of "No. B1: Vehicle runs in N range".





No. G2: Creep Force is Large

Description:

Vehicle accelerates in D, 3, 2, L, and R ranges though the accelerator pedal is not stepped on.

Possible Cause:

Too high engine idling speed (not attributable to AT).

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.

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.

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.