2004 ISUZU TF SERIES Tcm

7A2-110 DIAGNOSIS (JR405E)
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 9
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.

7A2-112 DIAGNOSIS (JR405E)
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 engine speed and other engine system correct?
Go to Step 5
Repair the defect or
replace.
5 Inspection of electrical or mechanical fault
Is the signal from each pressure switch changed synchronously?
Control Valve

TCM
B1
B12
B20 RED/YEL
WHT/BLK 2-4 Brake Pressure SW
Te r m i n a l
Assembly
YEL
E54
(7)
(12)
(1)H23
(12)
(10)C95
(1)
(12)
(20) RED/YEL
YEL
WHT/BLK
L&R Brake Pressure SW
High Clutch Pressure SWH22
(8)
Range TCM terminal
GearB20
(High clutch
pressure SW)B1
(2-4 brake pressure
SW)B12 (Low & reverse
brake pressure SW)
P - More than 10V More than 10V More than 10VR Reverse More than 10V More than 10V -N - More than 10V More than 10V More than 10VD, 3, 2 1st More than 10V More than 10V More than 10V2nd More than 10V - More than 10V3rd - More than 10V More than 10V4th - - More than 10VL 1st More than 10V More than 10V -2nd More than 10V - More than 10V3rd - More than 10V More than 10V4th - - More than 10VGo to Step 6
Repair the defect or
replace.

DIAGNOSIS (JR405E) 7A2-113
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.
8 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 9
Check the power
source harness and
earth harness (bolt
tightening to the
body).
9 Is the stall revolution correct in D, 3, 2 and L range? Refer the
STALL TEST section in this manual.
Go to Step 10
Repair the defect or
replace.
10 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) 7A2-115
No. D1: Faulty Gear Shifting (Different from Shift Pattern)

Description:

Gear is shifted, different from the specified shift pattern.

Diagnosis Hints:

When inspecting faulty gear shifting, it is important to distinguish between the fault of electric system and
mechanical system (AT main unit).

Fault of electric system.
Monitor the output signal (each solenoid driving signal) using with Tech 2. If a trouble signal is sent to the solenoid synchronously with the faulty gear shifting, the fault is originated in the electric system.
Monitor the input signal (signal from each sensor) using with Tech 2 and find an input signal by which the output signal (each solenoid driving signal) is subjected to fault.
Fault of the electric system may be derived from temperature or vibration. For instance, though the engine is normal while it is cold, fault may occur when the engine is warmed up or vehicle is running.

Fault of mechanical system.
If the gear is incorrectly shifted irrespective of operating signal (ON-OFF) of each solenoid, the faulty is originated from the machine system (AT).
If the clutch slips, ATF smells burnt, contaminated to be black or the stall speed increases.

Possible Cause:

Disordered select cable.

Disordered inhibitor switch.

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

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 "Faulty gear shifting" 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.







Incorrect properties of throttle opening signal (serial communication) of throttle position sensor.
The throttle opening signal which is sent by serial communication from ECM and TCM is an important
signal for gear shifting. In case of ECM fault or when the throttle position sensor does not issue voltage
signal according to the throttle opening, the gear is not shifted by stepping over the accelerator.
If the output voltage of the throttle position sensor changes freely even though the throttle opening is
constant, the gear is shifted incorrectly.




Faulty speed sensor.

DIAGNOSIS (JR405E) 7A2-117
Step Action Yes No
5 Inspection of electrical or mechanical fault
Is signal to each solenoid and pressure switch changed
synchronously to the faulty gear shift?

Control Valve


TCM


B1





B12





B20 RED/YEL
WHT/BLK 2-4 Brake Pressure SW

Terminal
Assembly
YEL
E54

(7)





(12)





(1) H23

(12)





(10)C95

(1)





(12)





(20) RED/YEL
YEL
WHT/BLK
L&R Brake Pressure SW

High Clutch Pressure SW

H22

(8)
Control Valve

TCM
B6
B7
B8
B9
B22 (GND) BLU/BLK
WHT/BLU L&R Brake Solen oid

Te r m i n a l
Assembly
BLK/YEL
RED
2-4 Brake Solenoid

High Clutch Solenoid

Low Clu tch S olen oid

E54
(5)
(9)
(10)
(3)
(11)H23
(11)
(5)
(7)
(2)
(1)
GRY/REDC95
(6)
(7)
(8)
(9)
(22) BLU/BLK
BLK/YEL
RED
WHT/BLU
GRY/RED
Range TCM terminal
GearB20
(High clutch
pressure SW)B1
(2-4 brake pressure
SW)B12 (Low & reverse
brake pressure SW)P - More than 10V More than 10V More than 10VR Reverse More than 10V More than 10V -N - More than 10V More than 10V More than 10VD, 3, 2 1st More than 10V More than 10V More than 10V2nd More than 10V - More than 10V3rd - More than 10V More than 10V4th - - More than 10VL 1st More than 10V More than 10V -2nd More than 10V - More than 10V3rd - More than 10V More than 10V4th - - More than 10V
Range TCM terminal
GearB8
(High clutch
solenoid)B9
(Low clutch
solenoid)B7
(2 -4 b rake
solenoid)B6
(Lo w & reve rs e
brake solenoid)P - Approx. 6.8V
(AC range)- Approx. 6.8V
(AC range)Approx. 6.2V
(AC ra ng e)
R Reverse Approx. 6.8V
(AC range)- Approx. 6.8V
(AC range)-
N - Approx. 6.8V
(AC range)- Approx. 6.8V
(AC range)Approx. 6.8V
(AC ra ng e)
D, 3, 2 1st Approx. 6.8V
(AC range)- Approx. 6.8V
(AC range)Approx. 6.8V
(AC ra ng e)
2nd Approx. 6.8V
(AC range)- - Approx. 6.8V
(AC ra ng e)
3rd - - Approx. 6.8V
(AC range)Approx. 6.8V
(AC ra ng e)
4th - Approx. 6.8V
(AC range)- Approx. 6.8V
(AC ra ng e)
L 1st Approx. 6.8V
(AC range)- Approx. 6.8V
(AC range)-
2nd Approx. 6.8V
(AC range)- - Approx. 6.8V
(AC ra ng e)
3rd - - Approx. 6.8V
(AC range)Approx. 6.8V
(AC ra ng e)
4th - Approx. 6.8V
(AC range)- Approx. 6.8V
(AC ra ng e)
Go to Step 6
In case of fault in
the machine
system, repair that
portion or replace
the unit.
Slip of clutch or fault
of control valve.

7A2-118 DIAGNOSIS (JR405E)
Step Action Yes No
6 Inspection of inhibitor switch using a Tech 2 or circuit tester.
Inspect the output voltage and throttle opening signal of the
throttle position sensor using a Tech 2 or circuit tester.

Inhibitor SW

TCM
A2 (P)
A17 (3)
B2 (2)
B10 (N)
B11 (D)
B19 (R)
B21 (L)
C95
(2 )
(10)
(11 )
(19)
(21) Y E L /V IO
RED/BLK
BLUBLK/GRN
Starter Relay
C94
(2 )
(3 )
BH22
(1)
(6)
(4)
(7)
(5)
(2) P
2
R
N
D
3
L
Start SW
PNK/BLU
E51
(2)
(4)
(8)
(5)
(1)
(9)
(6)
(3)
(10)
(7)
(38)
(15)
(3)
(37)
H4PNK/BLK
RED/YEL Y E L /V IO
BLK/GRN
PNK/BLK RED/BLK
BLU RED/YEL
PNK/BLU
BLK/WHT
BLK
BLK BLK/WHT Key Switch WHT
WHT
ICU (W/ Immobilis e r)
Ground (W/O Immobilis e r)
TCM terminal
RangeA2 B19 B10 B11 B17 B2 B21
P10 –
14.5V-- - - - -
R-10 –
14.5V-- ---
N--10 –
14.5V----
D - - - 10 –
14.5V---
3----10 –
14.5V--
2-----10 –
14.5V-
L------10 –
14.5V
Go to Step 7
Adjust the inhibitor
switch.
7 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 8
Repair the defect or
replace.

DIAGNOSIS (JR405E) 7A2-119
Step Action Yes No
8 Inspect the output signal of the speed sensor using a Tech 2 or
circuit tester.
Is the data display in the Tech 2 correct or output voltage correct
in the circuit tester?


Speed
SensorTCM
B13
H23
(4)C95
(13)E30
(2)
(1)
(3)
E10
Key SW
YEL/RED WHT
BLKYEL/RED
TCM terminal
ConditionB13
20km/h at L range in 1st gear Approx. 6.5V (AC range)Go to Step 9
Repair the defect or
replace.
9 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 10
Check the power
source harness and
earth harness (bolt
tightening to the
body).
10 Is the stall revolution correct in D, 3, 2 and L range? Refer the
STALL TEST section in this manual.
Go to Step 11
Repair the defect or
replace.
11 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.

7A2-120 DIAGNOSIS (JR405E)
No. D2: Gear is Shifted Frequently

Description:

Gear is shifted down immediately though the accelerator pedal is stepped on a little in D, 3, 2, or L range.

Diagnosis Hints:

Basically, the same cause as "No. D1: Faulty gear shifting" is considered. However, as possible cause, fault
input signal of throttle position sensor or speed sensor, fault input signal of inhibitor switch, or fault of TCM
power source, earth, ground return wire are considered first.

Then, slip of the clutch, fault of the control valve are considered.





No. D3: Gear Shift Point is Low or High at All Point
No. D4: Gear Shift Point is Low or High at Limited Point

Description:

Gear shift point is deviated from the shift diagram.

Gear is not shifted up properly though the vehicle is accelerated.

Gear is not shifted immediately and enough acceleration cannot be obtained though the accelerator pedal is
stepped on.

Diagnosis Hints:

If the cause is not faulty gear shift, throttle position sensor disordered or fault input of speed sensor is
considered. Output signal of the throttle position sensor is changed to linear one.
(Refer the paragraph about the faulty throttle position sensor of "No. D1: Faulty gear shifting".)





No. D5: No Kick-down

Description:

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

Diagnosis Hints:

When the gear shift is normal only without kick-down, possibility of fault of the throttle position sensor. Check
that the throttle voltage increases linearly in proportion to the throttle opening.
(Refer the paragraph about the faulty throttle position sensor of "No. D1: Faulty gear shifting".)