Valve body ISUZU TF SERIES 2004 Workshop Manual

BRAKE CONTROL SYSTEM 5A-21

Computer System Service Precautions
The Anti-lock Brake System and Electronic Brake-force
Distribution interfaces directly with the Electronic
Hydraulic Control Unit (EHCU) which is a control
computer that is similar in some regards to the Engine
Control Module. These modules are designed to
withstand normal current draws associated with vehicle
operation. However, care must be taken to avoid
overloading any of the EHCU circuits. In testing for
opens or shorts, do not ground or apply voltage to any
of the circuits unless instructed to do so by the
appropriate diagnostic procedure. These circuits should
only be tested with a high impedance multimeter
5-8840-0366-0 or special tools as described in this
section. Power should never be removed or applied to
any control module with the ignition in the “ON”
position.
Before removing or connecting battery cables, fuses or
connectors, always turn the ignition switch to the “OFF”
position.

General Service Precautions
The following are general precautions which should be
observed when servicing and diagnosing the Anti-lock
Brake System and/or other vehicle systems. Failure to
observe these precautions may result in Anti-lock Brake
System and Electronic Brake-force Distribution
damage.
 If welding work is to be performed on the vehicle
using an electric arc welder, the EHCU and valve
block connectors should be disconnected before
the welding operation begins.
 The EHCU and valve block connectors should
never be connected or disconnected with the
ignition “ON”.
Note:
 If only rear wheels are rotated using jacks or drum
tester, the system will diagnose a speed sensor
malfunction and the “ABS and Brake” warning lamp
will illuminate. But actually no trouble exists. When
the DTC is not detected and the ABS and BRAKE
warning lamp is on, “How to erase code” is
performed and a ABS and BRAKE warning lamp
are off.
If the battery has been discharged
The engine may stall if the battery has been completely
discharged and the engine is started via jumper cables.
This is because the Anti-lock Brake System (ABS) and
Electronic Brake-force Distribution (EBD) System
requires a large quantity of electricity. In this case, wait
until the battery is recharged, or set the ABS and EBD
to a non-operative state by removing the fuse for the
ABS. After the battery has been recharged, stop the
engine and install the ABS fuse. Start the engine again,
and confirm that the ABS warning Lamp does not light.
Note on Intermittents
As with virtually any electronic system, it is difficult to
identify an intermittent failure. In such a case
duplicating the system malfunction during a test drive or
a good description of vehicle behavior from the
customer may be helpful in locating a “most likely”
failed component or circuit. The symptom diagnosis
chart may also be useful in isolating the failure. Most
intermittent problems are caused by faulty electrical
connections or wiring. When an intermittent failure is
encountered, check suspect circuits for:
 Suspected harness damage.
 Poor mating of connector halves or terminals not
fully seated in the connector body (backed out).
 Improperly formed or damaged terminals.

Test Driving ABS Complaint Vehicles
In case that there has been an abnormality in the
lighting pattern of “ABS” warning lamp, the fault can be
located in accordance with the “DIAGNOSIS BY “ABS”
WARNING LAMP ILLUMINATION PATTERN”. In case
of such trouble as can be detected by the driver as a
vehicle symptom, however, it is necessary to give a test
drive following the test procedure mentioned below,
thereby reproducing the symptom for trouble diagnosis
on a symptom basis:
1.
Start the engine and make sure that the “ABS” W/L
goes OFF. If the W/L remains ON, it means that
the Diagnostic Trouble Code (DTC) is stored.
Therefore, read the code and locate the fault.
Note: The DTC cannot be cleared if the vehicle speed
does not exceed about 6km/h (4mph) at DTC, even
though the repair operation is completed.
2. Start the vehicle and accelerate to about 30 km/h
(19 mph) or more.
3. Slowly brake and stop the vehicle completely.
4. Then restart the vehicle and accelerate to about 40
km/h (25 mph) or more.
5. Brake at a time so as to actuate the ABS and stop
the vehicle.
6. Be cautious of abnormality during the test. If the
W/L is actuated while driving, read the DTC and
locate the fault.
7. If the abnormality is not reproduced by the test,
make best efforts to reproduce the situation
reported by the customer.
8. If the abnormality has been detected, repair in
accordance with the “SYMPTOM DIAGNOSIS” .
Note:

Be sure to give a test drive on a wide, even road
with a small traffic.
 If an abnormality is detected, be sure to suspend
the test and start trouble diagnosis at once.

BRAKES 5C-23

RTW35CSH001301

4) Failure on front master cylinder.
In case of failure on front master cylinder the pressure on
the inlet port (C) drop to zero. The pressure from inlet por
t
(A) acts on the bypass piston (2) and move it by comprising
of bypass spring (3). It makes possible the communication
between the inlet port (A) to outlet port (B) through the
bypass system. The outlet pressure (B) reaches the inle
t
pressure (A) and the LSPV is bypassed.


Valve Maintenance
In the case to fluid lead or other a abnormalities, faulty valve
should be replaced.
Note:
The load sensing proportioning valve is not repairable and
must be replaced as a completed assembly.


LOAD SENSING PROPORTIONING
VALVE (LSPV) ADJUSTMENT
RTW35CSH000301

1. Fluid Pressure Measurement
1) Rear axle weight adjustment
With an axle eight meter, adjust the rear axle weight with
a person sitting in the driver’s seat and a weight loaded
in the rear body.
N (kg/lb)

MODEL Adjustment value
4

2 7845 (800/1764)
4
2 HIGH RIDE
4

4 9316 (950/2095)

RTW35CSH000101





2) Installation of a fluid pressure gauge
Remove the air bleeder of the left hand wheel front and
rear brakes. Bleed air out of the fluid pressure gauge
with the measurement hose of the fluid pressure gauge
installed.
Pressure Tester: Brake oil (Fluid pressure gauge)
5-8840-2190-0

ELECTRICAL-BODY AND CHASSIS 8A-11
SYMBOLS AND ABBREVIATIONS
SYMBOLS
Symbol Meaning of Symbol Symbol Meaning of Symbol


Fuse
Bulb



Fusible link
Double filament bulb



Fusible link wire
Motor


Switch
Variable resistor Rheostat


Switch
Coil (inductor), solenoid,
magnetic valve


Switch (Normal close type)





Contact wiring
Relay


Battery




Diode
Connector


Electronic Parts
Light emitting diode



Resistor
Reed switch


Speaker
Condenser



Buzzer
Horn


Circuit breaker
Vacuum switching valve

8A-12 ELECTRICAL-BODY AND CHASSIS
ABBREVIATIONS
Abbreviation Meaning of abbreviation Abbreviation Meaning of abbreviation
A Ampere (S) LH Left hand
ABS Anti-lock brake system LWB Long wheel base
ASM Assembly MPI Multipart fuel injection
AC Alternating current M/T Manual transmission
A/C Air conditioner QOS Quick On Start system
ACC Accessories RH Right hand
CARB Carburetor RR Rear
C/B Circuit breaker RWAL Rear wheel anti-lock brake system
CSD Cold start device SRS Supplemental restraint system
DIS Direct ignition system ST Start
EBCM Electronic brake control module STD Standard
ECGI Electronic control gasoline injection SW Switch
ECM Engine control module SWB Short wheel base
ECU Electronic control unit TCM Transmission control module
EFE Early fuel evaporation V Volt
42 Two-wheel drive VSV Vacuum switching valve
44 Four-wheel drive W Watt (S)
FL Fusible link WOT Wide open throttle
FRT Front W/ With
H/L Headlight W/O Without
IC Integrated circuit
IG Ignition
kW Kilowatt

ELECTRICAL-BODY AND CHASSIS 8A-431


No. Connector face No. Connector face
E-71

NOT USED E-80
(6VE1)
Cylinder revolution
E-72
(C24SE)
(6VE1)
Engine earth-A E-81
(6VE1)
Speed sensor
E-73
(6VE1)
Engine earth-A E-82
(6VE1)
Transmission wire
E-74
(C24SE)
(6VE1)
Engine earth-B E-83
(6VE1)
Oil temperature sensor
E-75
(C24SE)
(6VE1)
Oil pressure switch E-84
(C24SE)
Knock sensor
E-76
(6VE1)
EGR valve E-85
(C24SE)
MAP sensor
E-77
(C24SE)
O2 sensor E-86
(4JA1-L)
SilverThermo switch; QOS
E-77
(6VE1)
O2 sensor RH-Front E-87
(4JA1-L)
WhiteSolenoid CSD
E-78
(6VE1)
O2 sensor LH-Front E-88
(4JA1-L)
SilverThermo switch; EGR
E-79
(6VE1)
Neutral start switch E-89
(4JA1-L)
White

Immobilizer engine control unit

8A-440 ELECTRICAL-BODY AND CHASSIS


No. Connector face No. Connector face
X-1
Black
Relay ; Tail lamp X-8
(4JH1-TC)
BlackRelay ; Starter
X-2
(C24SE)
(6VE1)
Black Relay ; Front Fog lamp X-9
(6VE1)
(4JH1-TC)
BlackRelay ; Hazard-RH
X-2
(4JH1-TC)
Black Relay ; Front Fog lamp X-10
(6VE1)
(4JH1-TC)
BlackRelay ; Hazard-LH
X-3

Relay ; Horn X-11
BlackRelay ; Heater
X-4

Relay ; Dimmer X-12
BlackRelay ; Head lamp
X-5
(6VE1)
Black Relay ; Front Fog Lamp X-13
(6VE1)
(4JH1-TC)
BlackRelay ; ECM MAIN
X-5
(4JH1-TC)
Black Relay ; Spill valve X-14

BlackRelay ; A/C Compressor
X-6
(C24SE)
(6VE1)
Relay ; Starter X-15
BlackRelay ; Thermo
X-6
(4JA1-L)
Black Relay ; CSD X-16
(6VE1)
(4JH1-TC)
BlackDIODE
X-7

Relay ; Condenser Fan X-17
BlackDIODE

TROUBLESHOOTING 6 – 9
6. Overheating
Step Action Value(s) Yes No
1 Was the engine coolant level OK? —
Go to Step 2 Replenish the
coolant
2 Was the water leakage or the radiator restriction
found? (Include radiator cap) — Repair or
replace the
leakage part. Go to Step 3
3 Was the fan belt slippage found? — Tension or
replace the fan
belt. Go to Step 4
4 Was the fan clutch working completely? —
Go to Step 5 Replace the
fan clutch
assembly.
5 Was the oil leakage found from fan clutch? — Replace the
fan clutch
assembly Go to Step 6
6 Was the thermostat working normally? —
Go to Step 7 Replace the
thermostat.
7 Was the water pump working OK? —
Go to Step 8 Replace the
water pump
assembly.
8 Was the restriction by the foreign materials in the
cooling system found? For example, clog the water
hose between the cylinder body and radiator etc.. — Clean or
replace the
clog part. Go to Step 9
9 Was the water leakage found from the sealing cap
on the cylinder body? — Replace the
sealing cap or
replace the
cylinder body. Go to Step 10
10 Are any DTC stored? — Go to indicated
DTC. Solved

7. White Exhaust Smoke
Step Action Value(s) Yes No
1 Was the compression pressure OK? 3.0 MPa
(31.0 kg/cm2,
441 psi) at
200 rpm
Go to Step 2 Readjust the
valve clearance
or replace the
cylinder head
gasket or
cylinder liner or
piston or piston
ring or valve
and relation
parts.
2 Was the PCV (Positive Crankcase Ventilation) valve
working completely? —
Go to Step 3 Repair or
replace the
PCV valve.
3 Was the turbocharger working completely? —
Go to Step 4 Replace the
turbocharger.
4 Are any DTC stored? — Go to indicated
DTC Solved

TROUBLESHOOTING 6 – 13
10–3 Continuous noise
Step Action Value(s) Yes No
1 Was the fan belt tension OK? 9 – 13 mm
(0.35 – 0.51
in)
Go to Step 2 Adjust the fan
belt tension.
2 Was the cooling fan loose? — Tighten the
cooling fan Go to Step 3
3 Was noise coming from the generator? — Repair or
replace the
generator
and/or the
vacuum pump Go to Step 4
4 Was noise coming from the water pump? — Replace the
water pump Go to Step 5
5 Was noise coming from the cylinder head cover? — Readjust the
valve
clearance. Go to Step 6
6 Are any DTC stored? — Go to indicated
DTC Solved

10-4 Slapping noise
Step Action Value(s) Yes No
1 Was noise coming from the cylinder head cover? — Go to Step 2 Go to Step 4
2 Were valve clearances correct? 0.4 mm
(0.016 in)
both intake
and exhaustAdjust the
valve
clearances Go to Step 3
3 Were the rocker arms damaged? — Replace the
rocker arms Go to Step 4
4 Was the flywheel fixing bolt loose? — Tighten the
fixing bolt. Go to Step 5
5 Was noise coming from the cylinder body? — Go to Step 6 Go to Step 10
6 Inspect the crankshaft bearing and/or crankshaft.
Was the crankshaft bearing and/or crankshaft worn?— Replace the
worn parts Go to Step 7
7 Inspect the connecting rod bearing and/or crankpin.
Was the connecting rod bearing and/or crankpin
worn? —
Replace the
worn parts Go to Step 8
8 Inspect the connecting rod small end bushing and/or
piston pin.
Was the connecting rod small end bushing and/or
piston pin worn? —
Replace the
worn parts Go to Step 9
9 Inspect the piston and/or cylinder liner.
Was the piston and/or cylinder liner worn or
damaged? — Replace the
worn or
damaged parts Go to Step 10
10 Are any DTC stored? — Go to indicated
DTC Solved

6A – 2 ENGINE MECHANICAL
Disassembly ............................................................................................................... 6A- 47
Internal Parts........................................................................................................... 6A- 47
Major Components.............................................................................................. 6A- 47
Minor Components ............................................................................................. 6A- 56
Rocker Arm Shaft and Rocker Arm................................................................ 6A- 56
Cylinder Head .................................................................................................. 6A- 57
Piston and Connecting Rod ........................................................................... 6A- 59
Inspection and Repair................................................................................................ 6A- 61
Cylinder Head ......................................................................................................... 6A- 61
Rocker Arm Shaft and Rocker Arm ....................................................................... 6A- 68
Cylinder Body ......................................................................................................... 6A- 69
Camshaft ................................................................................................................. 6A- 77
Crankshaft and Bearing ......................................................................................... 6A- 79
Crankshaft Bearing Selection................................................................................ 6A- 83
Crankshaft Pilot Bearing........................................................................................ 6A- 85
Flywheel and Ring Gear ......................................................................................... 6A- 85
Piston....................................................................................................................... 6A- 86
Cylinder Head Gasket Selection............................................................................ 6A- 88
Connecting Rod ...................................................................................................... 6A- 90
Idler Gear Shaft and Idler Gear.............................................................................. 6A- 91
Timing Gear Case Cover ........................................................................................ 6A- 91
Reassembly ................................................................................................................ 6A- 93
Internal Parts........................................................................................................... 6A- 93
Minor Component ............................................................................................... 6A- 93
Rocker Arm Shaft and Rocker Arm................................................................ 6A- 93
Cylinder Head .................................................................................................. 6A- 94
Piston and Connecting Rod ........................................................................... 6A- 96
Positive Crankcase Ventilation (PCV) Valve ................................................. 6A- 99
Major Component................................................................................................ 6A- 101
Installation .................................................................................................................. 6A- 118
External Parts ......................................................................................................... 6A- 118
Lubrication System........................................................................................................ 6A- 126

ENGINE MECHANICAL 6A – 39

18. Radiator
1) Drain the engine coolant.
2) Remove the reservoir hose.
3) Remove the upper and lower hose.
4) Remove the fan guide.
5) Remove the radiator.


19. Fan

P1010034
20. Air cleaner
1) Remove the MAF sensor connector (4JA1TC/4JH1TC) from air cleaner duct.
2) Remove the air cleaner duct and the air cleaner box from engine room.
3) Remove the two air ducts from inter cooler (4JA1TC/4JH1TC).

21. Power Steering Pump Loosen the power steering pump adjust plate bolt, then
remove the power steering pump assembly. Place the
power steering pump assembly along with piping on the
body side.
22. Air conditioner compressor 1) Remove air compressor magnet connector.
2) Remove the air conditioner compressor. Place the air conditioner compressor along with piping on the body
side.
23. Engine Control Cable Remove the engine control cable from its bracket
(4JA1TC/4JH1TC) or the injection pump (4JA1T(L)).

24. Vacuum Piping Remove the vacuum pipe from the vacuum pump, the
EGR valve, injection pump FICD (4JA1T(L)).

25. Engine Harness 1) Remove following connectors from engine.

TPS connector

Oil pressure switch connector

Thermo switch connector

Injection pump connector

Engine earth

Thermometer unit connector

TDC sensor
2) Remove the clips fixing engine harness.
P1010009