oil ISUZU TF SERIES 2004 Workshop Manual

DIAGNOSIS (JR405E) 7A2-77
Step Action Yes No
6 Is the quantity of ATF correct?
Go to Step 7
Correct the quantity of
ATF.
Go to Step 9
7 Connect the Tech 2 and test the solenoids of respective
solenoids for low & reverse brake, 2-4 brake, high clutch and
low clutch. Is operation sound heard from each solenoid?
Go to Step 8
Replace the solenoid
that does not generate
the operation sound.
Go to Step 9
8 Check the line pressure during the idling and at the engine stall
speed. Is the line pressure correct?
Go to Step 10
Either control valve, oil
pump or power train
parts (clutch, brake)
will be faulty. Replace
or overhaul the
transmission unit.
Go to step 10
9 Run the vehicle, and is the gear shifted from 1st to 4th
correctly?
Go to Step 10
Either control valve, oil
pump or power train
parts (clutch, brake)
will be faulty. Replace
or overhaul the
transmission unit.
Go to step 10
10 Clear the DTC from the memory and perform the work after
repair. Is the same DTC code outputted again in the
subsequent DTC check?
Replace the TCM Go to Step 11
11 Are the other DTCs outputted?
Go to Other DTC
Section Action is completed

7A2-78 DIAGNOSIS (JR405E)
DTC P1750 (Flash Code 51) Low & Reverse Brake Fail-safe Valve Failure

Low & Reverse Brake Fail Valve (B)Control Valve Upper Body
Low & Reverse Brake Fail Valve (A)Control Valve Lower Body

Setting Condition:

When the oil pressure generated and low & reverse brake pressure switch operates off/on twice, the TCM
detected an operation failure of the low & reverse brake fail-safe valve in D, 3, 2, L range.

Fail Safe:

When the vehicle is running, the gear position selected at the trouble detection is held and the lock-up is
inhibited.

After the vehicle stopped, all solenoid operations stop (OFF) and the gear is fixed to the 3rd.

Possible Cause:

Stick of low & reverse brake fail-safe valve.

Low & reverse brake pressure switch does not turn on.

Short circuit to ground of harness low & reverse brake pressure switch.

Poor connection of each connector of harness in low & reverse brake pressure switch.

7A2-80 DIAGNOSIS (JR405E)
DTC P1755 (Flash Code 52) 2-4 Brake Fail-safe Valve Failure

Control Valve Upper Body2-4 Brake Fail Valve (B)
Control Valve Lower Body2- 4 Br ake Fai l Val ve ( A)

Setting Condition:

When the oil pressure generated and 2-4 brake pressure switch operates off/on twice, the TCM detected an
operation failure of the low & reverse brake fail-safe valve in D, 3, 2, L range.

Fail Safe:

When the vehicle is running, the gear position selected at the trouble detection is held and the lock-up is
inhibited.

After the vehicle stopped, all solenoid operations stop (OFF) and the gear is fixed to the 3rd.

Possible Cause:

Stick of 2-4 brake fail-safe valve.

2-4 brake pressure switch does not turn on.

Short to ground of harness 2-4 brake pressure switch.

Faulty fitting of each connector of harness in 2-4 brake pressure switch.

DIAGNOSIS (JR405E) 7A2-91
SYMPTOM DIAGNOSIS

Symptom Condition Description
Oil Leak Breather Oil leaks from breather. J1
Between engine and converter housing Oil leaks between engine and converter
housing. J2
Between converter housing and main caseOil leaks between converter housing and
main case. J3
Between main case and rear housing Oil leaks between main case and rear
housing. J4
Oil pan Oil leaks from oil pan. J5
Manual shaft oil seal Oil leaks from manual shaft oil seal. J6
Oil cooler pipe Oil leaks from oil cooler pipe joint. J7
Other Transmission overheat You smell the transmission burning. Z1

The transmission smokes.
Mode lamp does not light up when the
power mode or 3rd start mode is turned on
The mode lamp on the instrument panel
does not light up though the power mode or
3rd start mode is turned on with the ignition
switch in ON position.
Z2
Mode lamp lights up when the power mode
or 3rd start mode is turned off
The mode lamp on the instrument panel
lights up though the power mode or 3rd start
mode is turned off with the ignition switch in
ON position.
Z3
Oil temperature warning lamp lights up Sometimes, the oil temperature warning
lamp lights up. Z4
Select lever feeling is faulty Select lever feeling is faulty. Z5
Poor fuel consumption Poor fuel consumption. Z6
Pattern select switch is faulty Shift pattern does not change though the
pattern select switch is turned on. Z7
Oil is splashed during the running Oil is splashed during the running. Z8
Abnormal smell Abnormal smell. Z9
Oil quantity is low or high Oil quantity is low or high. Z10
Abnormal oil pressure Oil pressure is low or high. Z11
Reverse buzzer does not ring Reverse buzzer does not ring in R range. Z12

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.

7A2-96 DIAGNOSIS (JR405E)
No. B1: Vehicle Runs in N Range

Description:

Creep appears in N range.

Vehicle moves unless the brake pedal is stepped on in N 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, low one-way clutch, reverse clutch, low & reverse brake).

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

Dislocated select lever (the select indicator light indicates the N range but the hydraulic system is in the D, 3, 2
or L range).

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.

Trouble in the AT
assembly or control
valve.

If ATF is extremely
black and
contaminated and
smells burnt, slip of the
clutch is supposed.
Overhaul the AT unit.

7A2-100 DIAGNOSIS (JR405E)
No. B3: Engine Race Up During Starting (Slip)

Description:

The engine speeds up but vehicle speed does not increase when the accelerator pedal is stepped on at the
starting.

Diagnosis Hints:

Possibility of slip of clutch is supposed. If slip of clutch has occurred, a DTC of "Gear ratio error" is stored.

Possible Cause:

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

Dropped line pressure.

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

7A2-104 DIAGNOSIS (JR405E)
No. B5: Engine Stalls When Selecting From N Range to
R, D, 3, 2 or L Range

Description:

The engine stalls when selecting from N or P range to a run range during the engine idling.

Diagnosis Hints:

As causes attributable to the engine, faulty idle up, insufficient engine output, etc. are considered.

As a cause of the AT system, faulty lockup piston system (lockup engine stall) is considered.

If the oil through resistance increases remarkably due to clogged oil cooler or some other reason, or if the ATF
level decreases, the lock-up piston works causing the engine stall.

Possible Cause:

Disordered idling speed, faulty idle up, faulty engine output, shortage output.

Insufficient ATF quantity (dropped level).

Clogged oil cooler (foreign substance mixed in).

Faulty lock-up piston (clogged oil passage of solenoid drive circuit, faulty operation).

Step Action Yes No
1 Gear ratio trouble diagnosis.
Travel in the following sequence for about 7 seconds or more in
each range: Start in the L range (1st) to 2 range (2nd) to 3 range
(3rd) to D range (4th) (to detect the gear ratio trouble exactly, this
process should be carried out)
Go to Step 2 Go to Step 2
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 Check of engine idle up speed
Does the idle speed increase when the air conditioning or other
electric load is turned on?
Go to Step 5
Repair the defect or
replace.