ECU ISUZU TF SERIES 2004 User Guide

4C1-22 FRONT WHEEL DRIVE

Legend
1. UJ Case
2. Bellows



8. Install band. Note the setting direction. After installation,
check Standard Caulk Measure.
Discard the used band and install a new one.
Use the special tool pliers 5-8840-2745-0 to caulk the band
to the specified value.
For both sides on UJ bellows.





Standard Caulk Measure

1.2mm (0.05in) <= (1), (2) <= 4.0mm (0.16in)

(1) - (2) or (2) - (1) <= 0.4mm (0.016in)
9. Install another bellows and fix band.
Discard the used band and install a new one.
10. Install the ball guide with the smaller diameter side ahead
onto the shaft.
11. Install ball retainer.

12. Using snap ring pliers, install the snap ring (1) securing the
ball retainer to the shaft.
Discard the used snap ring and install a new one.

BRAKE CONTROL SYSTEM 5A-3

DTC C0235 (Flash Code 35) Rear Left Wheel Speed Sensor Short Circuit or
Circuit Open .................................................................................................................... 5A-62
DTC C0236 (Flash Code 36) Rear Left Wheel Speed Sensor Incorrect Signal ............. 5A-64
DTC C0237 (Flash Code 37) Rear Left Wheel Speed Sensor Signal - Tooth
Chipping ........................................................................................................................... 5A-66
DTC C0238 (Flash Code 38) Tire Diameter Error ............................................................. 5A-68
DTC C0241 (Flash Code 41) Front Right Isolation Solenoid Circuit Open or
Shorted to Ground ........................................................................................................... 5A-69
DTC C0242 (Flash Code 42) Front Right Dump Solenoid Circuit Open or Shorted
to Ground.......................................................................................................................... 5A-69
DTC C0243 (Flash Code 43) Front Right Isolation Solenoid Circuit Shorted to
Battery............................................................................................................................... 5A-69
DTC C0244 (Flash Code 44) Front Right Dump Solenoid Circuit Shorted to
Battery............................................................................................................................... 5A-69
DTC C0245 (Flash Code 45) Front Left Isolation Solenoid Circuit Open or
Shorted to Ground ........................................................................................................... 5A-71
DTC C0246 (Flash Code 46) Front Left Dump Solenoid Circuit Open or Shorted
to Ground.......................................................................................................................... 5A-71
DTC C0247 (Flash Code 47) Front Left Isolation Solenoid Circuit Shorted to
Battery............................................................................................................................... 5A-71
DTC C0248 (Flash Code 48) Front Left Dump Solenoid Circuit Shorted to
Battery............................................................................................................................... 5A-71
DTC C0251 (Flash Code 51) Rear Isolation Solenoid Circuit Open or Shorted to
Ground .............................................................................................................................. 5A-73
DTC C0252 (Flash Code 52) Rear Dump Solenoid Circuit Open or Shorted to
Ground .............................................................................................................................. 5A-73
DTC C0253 (Flash Code 53) Rear Isolation Solenoid Circuit Shorted to Battery ......... 5A-73
DTC C0254 (Flash Code 54) Rear Dump Solenoid Circuit Shorted to Battery .............. 5A-73
DTC C0265 (Flash Code 65) Fail Safe Relay (FSR) Shorted to Ground ......................... 5A-75
DTC C0266 (Flash Code 66) Fail Safe Relay (FSR) Shorted to Battery.......................... 5A-75
DTC C0267 (Flash Code 67) ABS Motor Shorted to Ground .......................................... 5A-77
DTC C0268 (Flash Code 68) ABS Motor Shorted to Battery ........................................... 5A-77
DTC C0271 (Flash Code 71) ECU Failure or Valve +B Circuit Open .............................. 5A-79
DTC C0274 (Flash Code 74) ABS Operation Long Time ................................................. 5A-80
DTC C0276 (Flash Code 76) G-Sensor Malfunction ........................................................ 5A-82

5A-28 BRAKE CONTROL SYSTEM

Isolation Valve Test
Purpose: The purpose of this test is to detect brake
pipe and valve line harness wire for wrong connections
and valve trouble.
This test will help you confirm the result of your repair
service including the removal/reinstallation of brake
pipe, valve line harness and valve.
Test conditions: The ignition key is in the “ON” position
with the four wheels lifted up. The brake pedal is
stepped on, released and stepped on again with the
parking brake released.
Test procedure:
1. Connect Tech 2 with the vehicle, and select
Actuaor Test from the menus.
2. Select a Solenoid Valve Test Menu from the
Actuaor Test Menus.

060L300002
3. Select Isolation Valve from the Valve Select Menus.
4. Step on the brake pedal.
5. Release the brake pedal.
6. Make sure that the Isolation Valve “ON” aimed at by
Tech 2 and the wheel locked position are the same.
If different, check brake pipe, valve line harness
wiring and H/UNIT. Repair is needed if abnormality
is found.
7. Conduct Step 2 through Step 5 above on all the
four wheels.

060L300002
CAUTION: When conducting this test, please
observe the following cautions.

1. Do not start the engine.
2. Lift up the vehicle at a level floor.





Secure a clearance from the floor surface
enough to allow the lifted tire to rotate.
3. Maintain the lift up.
4. Wipe the floor surface to remove water and oil
so that the surface may become unslippery.
5. Do not load the vehicle.





When lifting up the vehicle, be sure to
observe the lifting up points. Refer to
vehicle lifting points in 0A section.

BRAKE CONTROL SYSTEM 5A-29

Dump Valve Test
Purpose: The purpose of this test is to detect brake
pipe and valve line harness wire for wrong connections
and valve trouble.
This test will help you confirm the result of your repai
r
service including the removal/reinstallation of brake
pipe, valve line harness and valve.
Test conditions: The ignition key is in the “ON” position
with the four wheels lifted up. The brake pedal is
stepped on, released and stepped on again with the
parking brake released.
Test procedure:
1. Connect Tech 2 with the vehicle, and select
Actuator Test Function from the menus.
2. Select a Solenoid Valve Test Menu from the
Actuator Test Menus.

060L300002
3. Select Dump Valve from the Valve Select Meuns.
4. Step on the brake pedal.
5. Make sure that the Dump Valve “ON” aimed at by
Tech 2 and the wheel released position are the
same. If different, check brake pipe, valve line
harness wiring and H/UNIT. Repair is needed if
abnormality is found.
6. Conduct Step 2 through Step 5 above on all the
four wheels.

060L300002
CAUTION: When conducting this test, please
observe the following cautions.

1. Do not start the engine.
2. Lift up the vehicle at a level floor.





Secure a clearance from the floor surface
enough to allow the lifted tire to rotate.
3. Maintain the lift up.
4. Wipe the floor surface to remove water and oil
so that the surface may become unslippery.
5. Do not load the vehicle.





When lifting up the vehicle, be sure to
observe the lifting up points. Refer to
vehicle lifting points in 0A section.

BRAKE CONTROL SYSTEM 5A-31

Warning Lamp System Control Main Items DTC
(Flash
Code) Description
ABS Brake
(EBD)ABS EBD
C0248
(48) Front Left Dump Solenoid Circuit
Shorted to Battery



Solenoid (EHCU)
C0251
(51) Rear Isolation Solenoid Circuit Open or
Shorted to Ground



Solenoid (EHCU)
C0252
(52) Rear Dump Solenoid Circuit Open or
Shorted to Ground



Solenoid (EHCU)
C0253
(53) Rear Isolation Solenoid Circuit Shorted
to Battery



Solenoid (EHCU)
C0254
(54) Rear Dump Solenoid Circuit Shorted to
Battery



Solenoid (EHCU)
C0265
(65) Fail Safe Relay (FSR) Shorted to
Ground



Motor (EHCU)
C0266
(66) Fail Safe Relay (FSR) Shorted to
Battery



Relay (EHCU)
C0267
(67) ABS Motor Shorted to Ground



Motor (EHCU)
C0268
(68) ABS Motor Shorted to Battery



Motor (EHCU)
C0271
(71) ECU Failure or Valve +B Circuit Open



EHCU
C0274
(74) ABS Operation Long Time



EHCU

C0276
(76) G-Sensor Malfunction



Sensor or Wiring




Battery, Wiring or EHCU
(less than 9V) C0277
(77) Power Supply Low Input




Battery or Wiring
(less than 10V)
C0278
(78) Power Supply High Input



Battery or Wiring EHCU
C0282
(82) 4 Wheel Drive State Input Signal Failure



Wiring
C0285
(85) Assembly Error (G-sensor)



Vehicle (Sensor or EHCU)

*A : When three or more failure are detected, or when
failure containing both front wheels and each rear
wheels are detected, EBD warning lamp is "ON"
and control is canceled.
*B : ABS lamp is “OFF” when the ABS lamp is “ON”
after a repair until vehicles speed becomes more
than 6km/h (4mph) in the following ignition cycle
and failure is not detected.

BRAKE CONTROL SYSTEM 5A-79

DTC C0271 (Flash Code 71) ECU Failure or Valve +B Circuit Open



RTW45AMF000201

Step Action
Value(s) Yes No
1 Was the “Basic Diagnostic Flow Chart” performed?
- Go to Step 2 Go to Basic
Diagnostic
Flow Chart
2 1. Ignition “OFF”.
2. Check the EHCU circuit for an open, short to
ground, or short to voltage. Also, check the EHCU
ignition feed circuit for an open or short to ground
and the EHCU ground circuit for an open or short to
voltage.
3. If a problem is found, repair as necessary.
Was a problem found?
- Verify repair Go to Step 3
3 1. Ignition “ON,” engine “OFF.”
2. Select “Display DTCs” with the Tech 2.
Note: Perform the various tests (actuator test, test
run, brake test, etc.) then observe the DTC with a
Tech2.
Are any DTCs stored? - Go to Step 4 Verify repair
4 Replace EHCU.
Note : Check the EHCU type for specification, when
the EHCU is replaced.
(Specification ; 2WD model or 4WD model)
Was the action complete? - Verify repair -

5C-22 BRAKES

RTW35CSH001001






Operation
1) Outline
When the LSPV (Load Sensing Proportioning Valve)
detects a change in load weight, the load sensing spring
stretches.
Its reaction force is transmitted to the bottom of the load
sensing valve to secure an optimum rear wheel cylinde
r
fluid pressure break point in proportion to the actual load
weight.
Besides, if the front brake system should fail, the device is
designed to prevent the master cylinder fluid pressure from
decreasing and to apply it directly to the rear wheel cylinde
r
to obtain a sufficient braking performance.

RTW35CSH001101

2) Bellow cutting point.
The Force (F) keeps the main piston (1) the rest position.
The inlet pressure (A) and outlet pressure (B) are the same
as well as the inlet pressure (C) from front master cylinder.
The bypass piston (2) is kept on rest position by equilibrium
of the pressures (A) and (C) and the bypass spring load (3).

RTW35CSH001201

3) Cutting point.
The cutting point is given by relation between force (F), tha
t
is the load applied by suspension of the vehicle and the
main piston area (1). The cutting point is achieved when the
force generated by hydraulic pressure is upper than the
force (F) given by the load suspension. The main piston (1)
moves from the rest position closing the valve. In this
moment the inlet pressure (A) is upper than the outle
t
pressure (B). The bypass piston (2) continues on the res
t
position by equilibrium of (A) and (C) pressure.

5C-24 BRAKES

RTW35CSH000201
3) Rear wheel cylinder fluid pressure measurement
Step on the brake pedal until the fluid pressure of the
front wheel cylinder gets to 9.8Mpa (100kg/cm
2), and
check the rear wheel cylinder fluid pressure. (Read the
value of the front wheel cylinder fluid pressure 2
seconds after the measurement. When measuring the
L.S.V fluid pressure, keep the brake pedal pressed
down without stepping it down twice or releasing it.)
Rear Wheel Cylinder Fluid Pressure MPa (kg/cm
2)

2WD 6.77
0.83 (69.0
8.5)
2WD (With High Ride
Suspension), 4WD 6.77

0.83 (69.0

8.5)

RTW35CSH000401
2. Oil Pressure Adjustment
1) LSPV spring length adjustment
Loosen the adjust nut of the LSPV spring joint, and
adjust the length of the LSPV spring.
When the oil pressure is insufficient, turn the adjust nu
t
clockwise to extend the span “A”. When the oil pressure
is too high, turn the adjust nut counterclockwise to
reduce the span “A”.


2) After adjustment, tighten the lock nut securely.
Lock Nut Torque N
m (kg
m/lb in)
11-20 (1.1-2.0/95-174)

CAB 10-3



Important Operations - Removal
3. Room Mirror
Remove the screw and pull the room mirror to upper side.


8. Windshield Glass
Remove the windshield glass, carefully following the steps
listed below:
1) Use a knife to cut through part of the adhesive caulking
material.
2) Secure one end of a piece of steel piano wire (0.02 inches
in diameter) to a piece of wood that can serve as a handle.
3) Use a pair of needle nose pliers to insert the other end o
f
the piano wire through the adhesive caulking material at the
edge of the windshield glass.
4) Secure the other end of the piano wire to another piece o
f
wood.




5) With the aid of an assistant, carefully move the piano wire
with a sawing motion to cut through the adhesive caulking
material around the entire circumference of the windshield
glass.
6) Lift the windshield from the body.
7) Clean any remaining adhesive caulking material from the
area of the body which holds the windshield.
8) Use a soft rag and unleaded gasoline to wipe off an
y
adhesive remaining on the windshield glass.

10-8 CAB

Important Operation - Removal
3. Rear Window Glass
Remove the glass, carefully following the steps listed below :
1) Use a knife to cut through part of the adhesive caulking
material.
2) Secure one end of a piece of steel piano wire (0.02 inches
in diameter) to a piece of wood that can serve as a handle.
3) Use a pair of needle nose pliers to insert the other end o
f
the piano wire through the adhesive caulking material at the
edge of the rear window glass.
4) Secure the other end of the piano wire to another piece o
f
wood.




5) With the aid of an assistant, carefully move the piano wire
with a sawing motion to cut through the adhesive caulking
material around the entire circumference of the rear windo
w
glass.
6) Lift the rear window glass from the body.
7) Clean any remaining adhesive caulking material from the
area of the body which holds the rear window glass.
8) Use a soft rag and unleaded gasoline to wipe off an
y
adhesive remaining on the rear window glass.


Important Operation - Installation
3. Rear Window Glass
1) Clean the rear window glass bonding surface.
2) Use a soft rag and unleaded gasoline to wipe off an
y
adhesive remaining on the body.
3) Install the fastener tape to body panel flange.



4) Apply primer 1 sunster #435-40 or equivalent to the rear
window glass side bonding surface.
The primer should extend 23 mm (0.9 in.) form end of the
glass.