ISUZU TF SERIES 2004 Workshop Manual
Manufacturer: ISUZU, Model Year: 2004, Model line: TF SERIES, Model: ISUZU TF SERIES 2004Pages: 4264, PDF Size: 72.63 MB
Page 4121 of 4264
DIAGNOSIS (JR405E) 7A2-129
Step Action Yes No
6 Inspect the output voltage and throttle opening signal of the
throttle position sensor using a Tech 2 or circuit tester.
Is a voltage value in proportion to the throttle opening output?
TPSTCM
A16
C56
(28)C94
(16) RED/ WHT
C56
(49)
(38)
(57)
(69)ECM
A47 (GND)
A35 (Out put )
A26
A55 (+5V)
A69 (I dl e SW)
Go to Step 7
Repair the defect or
replace.
7 Check of power supply to and earth of TCM.
Are the power supply and earth proper?
TCM
A1 (+B)
B5
B15
H23
(15)C95
(5)
(15) BLK/YEL
BLK BLK Battery
C94
(1)
BLK
Go to Step 8
Check the power
source harness and
earth harness (bolt
tightening to the
body).
8 Is the stall revolution correct in D, 3, 2 and L range? Refer the
STALL TEST section in this manual.
Go to Step 6
Repair the defect or
replace.
9 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.
Page 4122 of 4264
7A2-130 DIAGNOSIS (JR405E)
No. F2: Engine Races Up During Acceleration (Slip)
Description:
The engine speed up when the accelerator pedal is stepped on for acceleration and the gear is shifted up or
down.
Only the engine speeds up but vehicle speed does not increase when the accelerator pedal is stepped on for
acceleration during the running.
Diagnosis Hints:
Basically same causes as "No. C1 - C8: Engine races up (slip) by shift up or shift down" are considered.
When the condition of No. C1-C8 grows worse, symptom of No. F2 results.
No. F3: Noise or Vibration During the Running in R, D, 3, 2 or L Range
Description:
Noise or vibration is generated in the vicinity of AT during the running.
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.
No. F4: Engine Brake Does Not Apply in L Range
Description:
The engine brake does not apply, allowing the vehicle to run freely when the accelerator pedal is released at low
speed in L range.
Possible Cause:
Slip of clutch (low & reverse brake)
If slip of clutch is caused, a DTC (gear ratio error) is stored.
Faulty input/output signal system.
Low & reverse brake duty solenoid
Faulty control valve (faulty operation, sticking).
Page 4123 of 4264
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).
Page 4124 of 4264
7A2-132 DIAGNOSIS (JR405E)
No. G3: Creep Force is small
Description:
Vehicle does not move though a run range is selected on a flat road during the idling.
Diagnosis Hints:
When the creep force is small in all ranges, low engine output is considered. Another possible cause is slip of
clutch. If the creep is normal only in the R range, operation of the fail-safe function due to a trouble in the electrical
system is considered.
Possible Cause:
Slip of clutch (low clutch).
If slip of clutch is caused, a DTC (gear ratio error) is stored.
Low engine output (low idling speed, out of injection timing, lowered compression pressure, etc.).
Shortage or faulty quality of ATF.
Disconnection or short circuit of solenoid valve output.
Clogged oil passage of solenoid valve output.
Faulty ground return line in AT assembly.
If the ground return line earth is faulty, clutch pressure may decrease causing slip of the clutch.
Trouble in the torque converter system (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 Are the idling speed and other engine system normal?
Go to Step 5
Repair the defect or
replace.
5 Is the stall revolution normal in D, 3, 2 and L range? Refer
the STALL TEST section in this manual.
Go to Step 6
Repair the defect or
replace.
6 Is the line pressure normal? Refer the LINE PRESSURE
TEST section in this manual. Trouble in the AT
assembly or control
valve.
Repair the defect or
replace.
Page 4125 of 4264
DIAGNOSIS (JR405E) 7A2-133
No. G4: Large Noise During Idling with the Vehicle in Stop State
Description:
The transmission is noisy during the idling speed in all ranges.
Diagnosis Hints:
Causes such as solenoid operating sound or faulty oil pump are considered.
Distinguishing to some extent is possible by stopping the solenoid operation temporarily, checking the correlation
for the former case and, changing the line pressure and confirming the correlation with noise.
As a matter of course, noise may be generated around the engine, for instance, other than the AT and should be
checked carefully.
Note:
When the noise is generated only at the time of gear shift, it may be the sound of flowing ATF or gear
noise. If the sound varies depending on the gear speed to be shifted, it may be the gear noise generated
from the planetary gear and its related components. If the sound varies depending on the vehicle
speed, it may be the gear noise of the output system, and if varying depending on the engine speed, it
may be the gear noise of the input system or faulty torque converter.
In either case, sound may be "noise" depending on the origin and resonance object. When the object
generating the sound (resonance object) and the sound source (vibration source) are different,
investigation of the cause may be difficult.
No. H1: Judder Occurs at the Lock-up
Diagnosis Hints:
The vehicle body judders at lock-up.
Diagnosis Hints:
Slip due to burning of the lockup piston or insufficient fastening due to dropped working pressure are considered.
Trouble diagnosis flow is basically the same as "No. I1: No lock-up".
Note:
When the lock-up piston has burnt, foreign material mixed in the oil cooler is considered. In such a
case, inspect the oil cooler circuit for clogging of the oil cooler.
No. H2: Large Lock-up Shock
No. H3: Lock-up Point is High or Low
Description:
Large shock is felt at lock-up.
Lock-up point is excessive high or low.
Diagnosis Hints:
Out of properties of input sensor or faulty lock-up piston pressure system are considered.
Trouble diagnosis flow is basically the same as "No. I1: No lock-up".
Page 4126 of 4264
7A2-134 DIAGNOSIS (JR405E)
No. I1: No Lock-up
Description:
Lockup is not performed in spite of the lock-up area.
Diagnosis:
Lockup is not performed in spite of the lock-up area.
Monitor the signal to the lock-up solenoid while carrying out a running test.
When the output signal to the lock-up solenoid is correctly sent causing no lock-up, clogged lock-up solenoid oil
passage or malfunction of the lock-up piston may be considered.
Even the lock-up area, the output signal to the lock-up solenoid is not sent, fault of the ATF thermo sensor
controlling the lockup is considered. (Lock-up is not operated at ATF temperature less than 11C or more than
128C.)
Note:
When the lock-up piston has burnt, foreign material mixed in the oil cooler is considered. In such a
case, inspect the oil cooler circuit for clogging of the oil cooler
Possible Cause:
ATF thermo sensor detects low oil temperature (Lock-up is prohibited temperature less than 10C.).
Clogged oil passage of lock-up duty solenoid.
Trouble in control valve body (faulty operation, sticking, clogged oil passage).
Step Action Yes No
1 Are any DTCs stored?
Go to DTC Chart Go to Step 2
2 Are the quantity, contamination and smell normal?
If the ATF level is
low, replenish up to
the specified level.
Go to Step 3
If ATF is extremely
black and
contaminated and
smells burnt, slip of
the clutch is
supposed.
Overhaul the AT
unit.
Page 4127 of 4264
DIAGNOSIS (JR405E) 7A2-135
Step Action Yes No
3 Inspection of electrical or mechanical fault
When the ATF oil temperature is above 20C and the vehicle
speed is 80km/h, is ON signal issued to the lock-up solenoid
using the Tech 2 or circuit tester?
Control Valve
TCM
B17
B23 BLK Lock-up Solenoid
Terminal
Assembly
VIO Line Pressure Solenoid
E54
(4)
(6)H23
(14)
(6)C95
(17)
(23) BLK
VIO
TCM terminal
Lock-upB17
At lock-up Approx. 2.2 - 9.0V (AC range)
At unlock-up Approx. 1.0 – 2.0V (AC range)
Clogged oil
passage of lock-up
solenoid or faulty
operation of lock-
up piston. Go to Step 4
4 Inspection of ATF oil thermo sensor.
Is the ATF oil temperature sensor terminal voltage correct?
After running using the Tech 2 data display function, is the ATF
temperature higher than 10C?
AT F
Te m p .
SensorTCM
B4 (+)
B14 (-)
H23
(8)
(3)C95
(4)
(1 4) BLU Te r m in a l
Assembly
BLU/BLKE54
(2)
(8) BLU
BLU/BLK
TCM terminal
Temperature (deg. C)
B4 (Output voltage)
201.55
401.08
600.7
800.5
1000.3
1200.2
Monitor the electric
system input
sensor signal and
find a signal
causing no lockup.
Repair the defect or
replace.
Page 4128 of 4264
7A2-136 DIAGNOSIS (JR405E)
No. J1: Oil Leaks from Breather
Description:
Oil leaks from breather.
Possible Cause:
ATF quantity is excessively.
No. J2: Oil Leaks Between Engine and Converter Housing
No. J3: Oil Leaks Between Main Case and Converter Housing
No. J4: Oil Leaks Between Main Case and Rear Housing
No. J5: Oil Leaks from Oil Pan
No. J6: Oil Leaks from Manual Shaft Oil Seal
No. J7: Oil Leaks from Oil Cooler Pipe Joint
Description:
Oil leaks between engine and converter housing.
Oil leaks between converter housing and main case.
Oil leaks between main case and rear housing.
Oil leaks from oil pan.
Oil leaks from manual shaft oil seal.
Oil leaks from oil cooler pipe joint.
Possible Cause:
Faulty oil seal or sealing of contact surface is considered.
No. Z1: Transmission Overheat
Description:
You smell the transmission burning.
The transmission smokes.
Possible Cause:
Slip of clutch.
If slip of clutch is caused, a DTC (gear ratio error) is stored.
Clogged oil cooler (foreign substance mixed)
ATF stirred excessively (too much ATF).
Faulty torque converter operating pressure.
Faulty lock-up piston.
Page 4129 of 4264
DIAGNOSIS (JR405E) 7A2-137
No. Z2: Mode Lamp (Power Drive or 3rd Start) Does Not Light Up
When The Power Mode or 3rd Start Mode is Turned On
Description:
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.
Possible Cause:
Faulty mode select switch is considered.
Bulb burn out.
No. Z3: Mode Lamp (Power Drive or 3rd Start) Lights Up When
The Power Mode or 3rd Start Mode is Turned Off
Description:
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.
Possible Cause:
Faulty mode select switch is considered.
No. Z4: Oil Temperature Warning Lamp Lights up
Description:
Sometimes, the oil temperature warning lamp lights up.
Possible Cause:
When the vehicle is stuck in the mud or continues to accelerate under overload, and ATF temperature exceeds
145 C, the oil temperature warning lamp lights up.
If the oil temperature warning lamp lights up under usual service condition, following causes are considered.
ATF level has increased for some fault.
Refer to "No. Z1: Transmission overheat".
Lights up due to error of the ATF oil thermo sensor.
No. Z5: Select Lever Feeling is Faulty.
Description:
Select lever feeling is faulty.
Possible Cause:
Disordered select cable.
Disordered select lever.
Faulty Manual plate.
Page 4130 of 4264
7A2-138 DIAGNOSIS (JR405E)
No. Z6: Poor Fuel Consumption
Description:
Poor fuel consumption.
Diagnosis Hints:
Basically same causes as "No. C1 - C8: Engine races up (slip) by shift up or shift down" are considered.
No. Z7: Pattern Select Switch is Faulty
Description:
Shift pattern does not change though the pattern select switch is turned on.
Possible Cause:
Faulty mode select switch is considered.
No. Z8: Oil is Splashed During the Running
Description:
Oil is splashed during the running
Possible Cause:
ATF quantity is too high.
No. Z9: Abnormal Smell
Description:
Abnormal smell.
Diagnosis Hints:
Basically a trouble in the AT main unit.
No. Z10: ATF Quantity is Low or High
Description:
Oil quantity is low or high.
Possible Cause:
In case of oil level is high.
ATF temperature is low when ATF quantity is checked.
In case of oil level is low.
ATF leaks is considered. Check the AT main unit and cooler circuit.