Transmission ISUZU TF SERIES 2004 Workshop Manual

CONSTRUCTION AND FUNCTION 7A1-25
TRANSMISSION CONTROL MODULE (TCM)

The TCM is fitted side of brake pedal by means of two stud bolts.

The TCM judges necessary line pressure, gear shifting point and lock-up operation based on electrical
signals from switches and sensors and sends appropriate signals to solenoids.















        




















 
 
 
 
 
 
 












      
  

Connect to White Connector Connect to Grey Connector


Figure 49. Pin Assignment

Pin No. Pin Assignment Pin No.Pin Assignment
B1 2-4 Brake Oil Pressure Switch A1 V BATT (Battery Back-up Power Supply)
B2 2 Range Switch A2 P Range Switch
B3 Turbine Sensor A3 Brake Switch
B4 ATF Thermo Sensor A4 3rd Start Indicator Lamp
B5 Ground A5 K-Line Signal (Tech 2 Serial Communication)
B6 Low & Reverse Brake Duty Solenoid A6 No Connection
B7 2-4 Brake Duty Solenoid A7 Engine Speed Sensor
B8 High Clutch Duty Solenoid A8 No Connection
B9 Low Clutch Duty Solenoid A9 No Connection
B10 N Range Switch A10 Vehicle Speed Sensor Out (2WD Only)
B11 D Range Switch A11 3rd START Select Switch
B12 Low & Reverse Brake Oil Pressure Switch A12 4L Mode Switch (4WD Only)
B13 Vehicle Speed Sensor A13 No Connection
B14 ATF Thermo Sensor Ground A14 No Connection
B15 Ground A15 No Connection
B16 No Connection A16 Throttle Position Sensor
B17 Lock-up Duty Solenoid A17 3 Range Switch
B18 Vign
Ignition Power Supply) A18 DIAG Switch (Test Switch)
B19 R Range Switch A19 A/T OIL TEMP Indicator Lamp
B20 High Clutch Oil Pressure Switch A20 CHECK TRANS Indicator Lamp
B21 L Range Switch A21 POWER DRIVE Indicator Lamp
B22 Ground (Shift Solenoid) A22 No Connection
B23 Line Pressure Solenoid A23 No Connection
B24 Vign (Ignition Power Supply) A24 POWER DRIVE Select Switch

CONSTRUCTION AND FUNCTION 7A1-27
Item Description
- 4L mode -
4L mode setting condition
4L switch: On
Vehicle speed: More than 5km/h
Above conditions are met at the same time.
4L mode reset condition
4L switch: Off
Vehicle speed: Less than 4km/h
Above conditions are met at the same time.

- Down slope mode -
Down slope mode setting condition
Brake switch: On
Engine idle condition: More than 2.5 seconds
Select lever position: D or 3 range
Vehicle speed: More than 55km/h
Vehicle speed change: More than 1km/h
Above conditions are met at the same time.
Down slope mode reset condition
Engine idle condition: Not idle condition
Select lever position: Other than D or 3 range
At least, one of above conditions is met.

- Power Mode -
When power drive switch is On at only D range or 3 range, the shift change is performed by
1 – 4 speed based on shift diagram set as power pattern.

- Up slope mode -
Up-slope reasoning value is calculated from the average throttle angle and the average
acceleration. Otherwise, up-slope reasoning value is calculated from the vehicle speed.
TCM judges as up-slope mode when the former is bigger than latter.


Lock-up control The lock-up solenoid adjusts the pressure based on the signal from the TCM according to
the vehicle speed, throttle opening and other input signals based on the pre-set lock-up
point to control the lock-up.
Smooth lock-up control engages and disengages the clutch smoothly at the time of lock-up.
When the oil temperature is low (below 20
C) or high (above 128
C), lock-up is prohibited
even when the vehicle is at a lock-up speed.
The lock-up is disengaged also when the throttle is closed.
Direct electronic shift
control (DESC)
The duty cycle type solenoid is used for each clutch and brake. The solenoid adjusts the
clutch pressure to be suited to the engine load and vehicle traveling condition based on the
signal from the TCM. The pressure switch provided in the control valve oil passage sends
the oil pressure condition to the TCM to control the disengagement and engagement of the
clutch and brake directly and finely.
Learning control Learning is controlled to correct the oil pressure control timing to engage or disengage the
clutch optimally in order to compensate changes of the engine performance and changes
of the transmission with time. It is controlled to bring the speed-change time closer to the
value pre-set to the TCM.

7A1-28 CONSTRUCTION AND FUNCTION
Item Description
Fail-safe function In case of malfunction of the vehicle speed sensor, throttle position sensor, all solenoids or
inhibitor switch, TCM automatically begins fail-safe control to minimize effects on driving.
The gear is fixed at the 3rd-speed position and power supply to the solenoid is shut off so
that the solenoid does not work nor lock up.
Self-diagnosis function Parts required for controlling the automatic transmission are provided with a self-diagnosis
function. When any trouble occurs, the check trans indicator lamp blinks to warn the driver.
The trouble code is memorized in the TCM.

CONSTRUCTION AND FUNCTION 7A1-33
LEARNING CONTROL

Oil pressure control timing is optimally corrected at the time of clutch engagement and disengagement
and controlled to bring the speed-change time to the value preset to the TCM and compensate the
changes of the engine performance and changes of the transmission with time.

When the gear is shifted, the clutch pressure 2 is optimally corrected so that the speed-change time is as
near as the target value
1 preset to the TCM and the changes in the engine performance and the
changes of the transmission with time can be compensated based on the past speed-change results.

When the clutch is operated to shift the gear, the time of the clutch oil pressure release timing 4 on the
disengagement side is optimally corrected so that the changes of the engine rpm
3 is optimum.


Note:

When the battery terminal is disconnected, contents of learning are cleared and resultantly the speed
change shock may increase. After the vehicle has traveled, learning is repeated and the shock
decreases gradually.





Figure 53. Learning Control

CONSTRUCTION AND FUNCTION 7A1-35
CONTROL CIRCUIT BLOCK DIAGRAM



Speed sensor
Turbine sensor
Brake switch
Inhibitor switch
Power drive, 3rd start
switch
ATF oil thermo sensor
High clutch oil pressure
switch
2-4 brake oil pressure
switch
Low & reverse brake oil
pressure switch
Transfer control module
(4WD Only)



Engine Control Module
(ECM)
Line pressure solenoid
Low clutch solenoid
High clutch solenoid
2-4 brake solenoid
Low & reverse brake
solenoid
Lock-up solenoid
ATF temperature
indicator lamp
Speed meter (2WD
Only)
Power, 3rd start indicator
lamp
Check trans indicator
lamp
Data link connector Self-diagnosis
function



Transmission
Control
Module
(TCM)
4L mode
Engine
speed
Throttle
angle
Figure 54. Control Circuit Block Diagram

7A1-36 CONSTRUCTION AND FUNCTION
GEAR TRAIN (TRANSMISSION MECHANISM) OPERATION AND
HYDRAULIC CIRCUIT
CONSTRUCTION AND OPERATION
The JR405E consists of two sets of planetary gears, three multiple plate clutches, two multiple plate brakes
and one one-way clutch.





COMPONENT NAME AND FUNCTION
Component Name Symbol Function
Low Clutch L/C Connects the front planetary carrier to the rear
internal gear.
Engaged at 1st, 2nd and 3rd gear.
High Clutch H/C Connects the input shaft to the front planetary
carrier.
Engaged at 3rd and 4th (O/D) gear.
Reverse Clutch R/C Connects the input shaft to the front sun gear.
Engaged at Reverse gear.
Low & Reverse Brake L&R/B Locks the front planetary carrier.
Engaged at L range and Reverse gear.
2-4 Brake 2-4/B Locks the front sun gear.
Engaged at 2nd and 4th (O/D) gear.
Low One-way Clutch L/O.C Allows the front planetary carrier to turn forward
(clockwise) but locks to opposite direction
(counterclockwise).
Operative when accelerating.
Low Clutch Solenoid L/C.S Regulates low clutch pressure.
High Clutch Solenoid H/C.S Regulates high clutch pressure.
Low & Reverse Brake Solenoid L&R/B.S Regulates low & reverse brake pressure.
2-4 Brake Solenoid 2-4/B.S Regulates 2-4 brake pressure.
Lock-up Solenoid L/U.S Regulates lock-up clutch pressure.
High Clutch Oil Pressure SW H/C.P/SW Detects high clutch supply oil pressure.
Low & Reverse Brake Oil Pressure SW L&R/B.P/SWDetects low & reverse brake supply oil pressure.
2-4 Brake Oil Pressure SW 2-4/B.P/SWDetects 2-4 brake supply oil pressure.

CONSTRUCTION AND FUNCTION 7A1-37
COMPONENT AND THEIR OPERATING CONDITION

Clutch Brake Solenoid Pressure Switch
Select
lever
position
Gear
position
Gear
Shift
Lock-
up
L/C
H/C
R/C
L/O.C
L&R/B
2-4/B
L/C.S
H/C.S
L&R/
B.S
2-4/
B.S
L/U.S H/
C.P/
SWL&R/
B.P/
SW2-4
B.P/
SW
P - -

R Reverse -

N - -

1st

2nd
3rd


D
4th

1st

2nd
3rd


3
4th(*1)


1st

2nd

3rd(*1)



2
4th(*1)


1st
2nd(*1)

3rd(*1)



L
4th(*1)



*1:Transmission is shifted at high speed to prevent engine over-run.
- Engaged or operated
- Operative when accelerating

7A2-4 DIAGNOSIS (JR405E)
PAGE
NO. D3: GEAR SHIFT POINT IS LOW OR HIGH AT ALL POINT................................. 7A2-120
NO. D4: GEAR SHIFT POINT IS LOW OR HIGH AT LIMITED POINT ......................... 7A2-120
NO. D5: NO KICK-DOWN .............................................................................................. 7A2-120
NO. E1: NO GEAR SHIFT .............................................................................................. 7A2-121
NO. E2: ONLY 4TH GEAR (O/D) IS NOT SELECTABLE ............................................. 7A2-124
NO. E3: GEAR IS SHIFTED 2ND TO 3RD IN 2 RANGE ............................................... 7A2-126
NO. E4: GEAR IS SHIFTED 1ST TO 2ND IN L RANGE................................................ 7A2-126
NO. E5: GEAR IS SHIFTED 3RD TO 4TH IN 3 RANGE................................................ 7A2-126
NO. F1: LOW MAXIMUM SPEED OR POOR ACCELERATION ................................... 7A2-127
NO. F2: ENGINE RACES UP DURING ACCELERATION (SLIP) ................................. 7A2-130
NO. F3: NOISE OR VIBRATION DURING THE RUNNING IN R, D, 3, 2 OR L
RANGE .......................................................................................................................... 7A2-130
NO. F4: ENGINE BRAKE DOES NOT APPLY IN L RANGE......................................... 7A2-130
NO. F5: ENGINE STALLS BEFORE VEHICLE STOPS FROM RUNNING ................... 7A2-131
NO. G1: VEHICLE MOVES IN P RANGE OR PARKING GEAR IS NOT
DISENGAGED OTHER THAN P RANGE ..................................................................... 7A2-131
NO. G2: CREEP FORCE IS LARGE.............................................................................. 7A2-131
NO. G3: CREEP FORCE IS SMALL .............................................................................. 7A2-132
NO. G4: LARGE NOISE DURING IDLING WITH THE VEHICLE IN STOP STATE ...... 7A2-133
NO. H1: JUDDER OCCURS AT THE LOCK-UP ........................................................... 7A2-133
NO. H2: LARGE LOCK-UP SHOCK .............................................................................. 7A2-133
NO. H3: LOCK-UP POINT IS HIGH OR LOW ............................................................... 7A2-133
NO. I1: NO LOCK-UP .................................................................................................... 7A2-134
NO. J1: OIL LEAKS FROM BREATHER ....................................................................... 7A2-136
NO. J2: OIL LEAKS BETWEEN ENGINE AND CONVERTER HOUSING .................... 7A2-136
NO. J3: OIL LEAKS BETWEEN MAIN CASE AND CONVERTER HOUSING.............. 7A2-136
NO. J4: OIL LEAKS BETWEEN MAIN CASE AND REAR HOUSING .......................... 7A2-136
NO. J5: OIL LEAKS FROM OIL PAN ............................................................................ 7A2-136
NO. J6: OIL LEAKS FROM MANUAL SHAFT OIL SEAL ............................................. 7A2-136
NO. J7: OIL LEAKS FROM OIL COOLER PIPE JOINT................................................ 7A2-136
NO. Z1: TRANSMISSION OVERHEAT .......................................................................... 7A2-136
NO. Z2: MODE LAMP (POWER DRIVE OR 3RD START) DOES NOT LIGHT UP
WHEN THE POWER MODE OR 3RD START MODE IS TURNED ON........................ 7A2-137

7A2-6 DIAGNOSIS (JR405E)
BASIC TROUBLE SHOOTING

Transmission fluid pressure together with clutch and brake friction and other important transmission functions are
controlled by electrical signal from the Transmission Control Module (TCM).
Random diagnosis can produce inaccurate and misleading indications. It is important that diagnosing procedure be
carried out systematically.
Carefully follow the sequence outlined below to diagnose automatic transmission assembly.




Verify Customer Complain
Preliminary Check
(Visual Check/Test Drive)
Compare to Same Model
(If Available)
Check Service Bulletin
DTC Check
(Self-diagnosis/Tech 2)
Go to Symptom Diagnosis
Stall Test
Line Pressure Test
Transmission Overhaul
Repair & Verify Fix
Transmission Overhaul
Transmission Overhaul
Go to DTC Chart
Go to Intermittent Diagnosis NG
Follow the instructions
NG
No Instruction
NG
OK
NO DTC
Not Solved
OK
OK
Follow the Bulletin
(Once Clear Memory) Restored
Not Stored
Use Service Programming
System (SPS)
Not Solved

DIAGNOSIS (JR405E) 7A2-9
DIAGNOSIS WITH TECH 2
In this JR405E transmission, troubleshooting can be performed for electrical faults using the Tech 2 scan tool.
If the "CHECK TRANS" lamp blinks, or if an electrical fault in the transmission may probably exit, check trouble
codes using the Tech 2 scan tool.
In the diagnostic procedures described in this manual, first repair the faulty positions indicated by trouble code in
order of numbers and then perform troubleshooting for the faulty positions that are not indicated by trouble code.
For correct troubleshooting, it is necessary to first repair the trouble codes of lower order numbers, then to repair
the trouble codes of higher order numbers in sequence.

If no codes are set:

Refer to F1: Data Display and identify the electrical faults that are not indicated by trouble code.

Refer to "SYMPTOM DIAGNOSIS".

If codes are set:
1. Record all trouble codes displayed by Tech 2 and check id the codes are intermittent.
2. Clear the codes.
3. Drive the vehicle for a test to reproduce the faulty status.
4. Check trouble codes again using the Tech 2.
5. If no codes is displayed by test driving, the fault is intermittent. In this case, refer to "INTERMITTENT
DIAGNOSIS".
6. If a code is present, refer to DTC Chart for diagnosis.
7. Check trouble codes again using the Tech 2.





TECH 2 CONNECTION
Tech 2 scan tool is used to electrically diagnose the automatic
transmission system and to check the system. The Tech 2
enhances the diagnosis efficiency though all the
troubleshooting can be done without the Tech 2.
1. Configuration of Tech 2

Tech 2 scan tool kit (No. 7000086), Tech 2 scan tool
(No. 7000057) and DLC cable (No. 3000095).

SAE 16/19 adapter (No. 3000098) (1), RS232 loop back
connector (No. 3000112) (2) and PCMCIA card (No.
3000117) (3).




2. Tech 2 Connection

Check the key switch is turn OFF.

Insert the PCMCIA card (1) into the Tech 2 (4).

Connect the SAE 16/19 adapter (2) to the DLC cable (3).

Connect the DLC cable (3) to the Tech 2 (4).

Connect the SAE 16/19 adapter (2) to the data link
connector of the vehicle.

Turn the key switch of the vehicle ON and press the
"PWR" key of the Tech 2.

Check the display of the Tech 2.