engine ISUZU TF SERIES 2004 Workshop Manual

DIAGNOSIS (JR405E) 7A2-81

Step Action Yes No
1 Turn the key switch on and check the DTC. Is only the DTC for
2-4 brake fail-safe valve failure outputted?
Go to Step 2
Go to Other DTC
Section
2 Clear the DTC from the memory. Turn the key switch off once,
and then start the engine. Does the CHECK TRANS blink when
the D range is selected and about 10 seconds elapsed?
Go to Other DTC
Section Go to Step 3
3 Run the vehicle, shift the gear from 1st to 4th, stop the vehicle,
and again shift the gear from 1st to 4th. Does the CHECK
TRANS blink at this time?
Go to Step 4
The 2-4 brake fail-safe
valve may be faulty
temporarily.
Go to step 5
4 Turn the key switch on and check the DTC. Is only the DTC for
the 2-4 brake fail-safe valve failure outputted?
Repair or replace the
control valve.
Go to Step 5
Go to Other DTC
Section
5 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 6
6 Are the other DTCs outputted?
Go to Other DTC
Section Action is completed

DIAGNOSIS (JR405E) 7A2-83
SYMPTOM DIAGNOSIS

Symptom Condition Description
Vehicle does not
run In D, 3, 2, L, and R ranges Vehicle does not run though the accelerator
pedal is stepped on. A1
In R range Vehicle does not run in R range only. A2
It runs normally in D, 3, 2, and L ranges.
In D, 3, 2, and L ranges Vehicle does not run in D, 3, 2, and L
ranges only. A3
It runs normally in R range.
Trouble at
starting Vehicle runs in N range Creep appears in N range. B1
Vehicle moves unless the brake pedal is
stepped on in N range.
Poor acceptation Starting acceleration is poor. B2
Engine races up during starting (slip)
The engine speeds up but vehicle speed
does not increase when the accelerator
pedal is stepped on at the starting.
B3
Large shock when shift lever is changed to
N to D range or N to R range
Large shock is felt when selecting D or R
range from N range during the idling after
warming up.
B4
Engine stalls when selecting from N range
to R, D, 3, 2, or L range
The engine stalls when selecting from N or
P range to a run range during the engine
idling.
B5
Engine starter does not run in P or N rangeThe engine starter does not run though the
P or N range is selected. B6
Engine starter runs except in P or N range The engine starter runs though the R or D,
3, 2or L range is selected. B7
Extended time lag when shift lever is
changed to N to D
The shift time lag is longer than standard
value when shift lever is changed to N to D.B8
Extended time lag when shift lever is
changed to N to R
The shift time lag is longer than standard
value when shift lever is changed to N to R.B9
Brake is applied in R range Brake is applied suddenly in R range. B10
Insufficient starting or shaking in D range Insufficient starting or shaking in D range. B11
Noise or vibration Noise or vibration is generated in the vicinity
of AT at starting. B12

DIAGNOSIS (JR405E) 7A2-85
SYMPTOM DIAGNOSIS

Symptom Condition Description
Faulty shifting Engine race up (slip) when gear is shifted up
to 1st to 2nd
The engine speed up when the accelerator
pedal is stepped on for acceleration and the
gear is shifted up.
C1
Engine race up (slip) when gear is shifted up
to 2nd to 3rd
The engine speed up when the accelerator
pedal is stepped on for acceleration and the
gear is shifted up.
C2
Engine race up (slip) when gear is shifted up
to 3rd to 4th
The engine speed up when the accelerator
pedal is stepped on for acceleration and the
gear is shifted down or for kick-down during
steady run.
C3
Engine race up (slip) when gear is shift
down or kick-down to 4th to 3rd
The engine speed up when the accelerator
pedal is stepped on for acceleration and the
gear is shifted down or for kick-down.
C4
Engine race up (slip) when gear is shift
down or kick-down to 4th to 2nd
The engine speed up when the accelerator
pedal is stepped on for acceleration and the
gear is shifted down or for kick-down.
C5
Engine race up (slip) when gear is shift
down or kick-down to3rd to 2nd
The engine speed up when the accelerator
pedal is stepped on for acceleration and the
gear is shifted down or for kick-down.
C6
Engine race up (slip) when gear is shift
down or kick-down to4th or 3rd to 1st
The engine speed up when the accelerator
pedal is stepped on for acceleration and the
gear is shifted down or for kick-down.
C7
Engine race up (slip) others
The engine speed up when the accelerator
pedal is stepped on for acceleration and the
gear is shifted down or for kick-down during
steady run.
C8
Braking feel when gear is shifted up to 1st to
2nd
Brake feeling appears when the accelerator
pedal is stepped on for acceleration and the
gear is shifted up.
C9
Braking feel when gear is shifted up to 2nd
to 3rd
Brake feeling appears when the accelerator
pedal is stepped on for acceleration and the
gear is shifted up.
C10
Braking feel when gear is shifted up to 3rd
to 4th
Brake feeling appears when the accelerator
pedal is stepped on for acceleration and the
gear is shifted up.
C11
Large shock when gear is shifted to 1st to
2nd or 2nd to 1st
Large shock is felt when the accelerator
pedal is stepped on for acceleration and the
gear is shifted up or down.
C12
Large shock when gear is shifted to 2nd to
3rd or 3rd to 2nd
Large shock is felt when the accelerator
pedal is stepped on for acceleration and the
gear is shifted up or down.
C13

7A2-86 DIAGNOSIS (JR405E)
Symptom Condition Description
Large shock when gear is shifted to 3rd to
4th or 4th to 3rd
Large shock is felt when the accelerator
pedal is stepped on for acceleration and the
gear is shifted up or down.
C14
Large shock when kick-down Large shock is felt when the accelerator
pedal is stepped on for kick-down. C15
Large shock when no acceleration Large shock is felt when the accelerator
pedal is not stepped on. C16
Large shock when gear is shifted down to
2nd to 1st in L range
Large shock is felt when the shift lever is
selected in L range. C17
Large shock (other)
Large shock is felt when the accelerator
pedal is stepped on for acceleration and the
gear is shifted up or down.
C18

Large shock when vehicle speed is downed
by no accelerator pedal or vehicle is
stopped.
Large shock is felt when the accelerator
pedal is not stepped on. C19
Large lock-up shock Large shock is felt at lock-up. C20
Shift down or engine over-run when the
accelerator pedal is stepped on in 4th gear
Shift down or engine over-run above the
kick-down area. C21

DIAGNOSIS (JR405E) 7A2-89
Symptom Condition Description
Faulty during the
running Low maximum speed or poor acceleration Starting acceleration is poor. F1
Acceleration is slow though the accelerator
pedal is stepped on during the running.
Engine races up during acceleration (slip)
The engine speeds up but vehicle speed
does not increase when the accelerator
pedal is stepped on at the starting.
F2

Only the engine speeds up but vehicle
speed does not increase when the
accelerator pedal is stepped on for
acceleration during the running.

Noise or vibration during the running in R, D,
3, 2, or L range
Noise or vibration is generated in the vicinity
of AT during the running. F3
Engine brake does not in apply L range
The engine brake does not apply, allowing
the vehicle to run freely when the
accelerator pedal is released at low speed in
L range.
F4
Engine stalls before vehicle stops from
running
The engine stalls simultaneously with the
vehicle stop when the brake pedal is
stepped on to stop the vehicle during the
running.
F5
Faulty in the
stopping
Vehicle moves in P range, or parking gear is
not disengaged other than P range
Vehicle moves though it stops at a slope
and P range is selected. G1

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

Creep force is large
Vehicle accelerates in D, 3, 2, L, and R
ranges though the accelerator pedal is not
stepped on.
G2
Creep force is small Vehicle does not move though a run range
is selected on a flat road during the idling. G3
Large noise during idling with the vehicle in
stop state
The transmission is noisy during the idling
speed in all ranges. G4
Faulty lock-up Judder occurs at the lock-up The vehicle body judders at lock-up. H1
Large lock-up shock Large shock is felt at lock-up. H2
Lock-up point is high or low Lock-up point is excessive high or low. H3
No lock-up No lock-up Lockup is not performed in spite of the lock-
up area. I1

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.

DIAGNOSIS (JR405E) 7A2-97
No. B2: Poor Acceleration at Starting

Description:

Starting acceleration is poor.

Diagnosis Hints:

In addition to the low engine output, faulty gear shifting of AT or fixing at the 3rd position may be possible.
Therefore, in case of such a trouble that "maximum speed is low, and acceleration is poor", it should be cleared
up whether the trouble is originated from the engine system of AT system by a running test, inspection of stall
revolution, etc.

Possible Cause:

Clogged air cleaner, out of injection timing, dropped compression pressure, etc.

Fixing at 3rd position (fail-safe activated).
Since the gear is fixed at the 3rd position because of the fail-safe function, a trouble that "Maximum
speed is low, and acceleration is poor" is resulted. In this case, the DTC is memorized.
When TCM stops operation because of faulty TCM ground, the gear is fixed at the 3rd position because
of a mechanical reason. In this case, no DTC is memorized.

Disordered inhibitor switch.

Incorrect properties of throttle opening signal (serial communication) of throttle position sensor.
Throttle opening signal (serial communication) of the throttle position sensor does not change in
proportion to the throttle opening. In this case, fixing at the high or low gear results in such a trouble
that "Maximum Speed is Low and Acceleration is Poor".

Slip of clutch (low clutch, high clutch).

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

Dropped line pressure.

Trouble in the torque converter system (faulty operation).

Step Action Yes No
1 Test Drive.
Is the gear smoothly shifted in the order of 1st to 2nd, 2nd to 3rd,
3rd to 4th gear and lock up?

Clogged air cleaner,
out of injection
timing, dropped
compression
pressure, etc.

Go to Step 2
2 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 3 Go to Step 3
3 Are any DTCs stored?
Go to DTC Chart Go to Step 4