check engine light 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.

BRAKE CONTROL SYSTEM 5A-27

Actuator Test (Tech 2)
There are 5 different menus available for this test. The
state of each circuit can be tested by using these
menus. Especially when DTC cannot be detected, a
faulty circuit can be diagnosed by testing each circuit by
means of these menus.
Even when DTC has been detected, the circuit tests
using these menus could help discriminate between a
mechanical trouble and an electrical trouble.
In all cases test condition; Engine stops with the key
turned to the “ON” position. To be more specific, the
test is conducted with the brake pedal stepped on after
stepping once and releasing.
 Engine: Stop
 Ignition SW: ON

060L300002

ABS Check Light Test
Test condition: Engine stops with the key turned to the
“ON” position. To be more specific, the test is
conducted with the brake pedal stepped on after
stepping once and releasing.
 The circuit is normal if the warning light (lamp) in
the meter panel comes on and goes out in
accordance with Tech2’s instruction.

060L300002

Return Pump Test
Test condition: Engine stops with the key turned to the
“ON” position. To be more specific, the test is
conducted with the brake pedal stepped on after
stepping once and releasing.
Make sure of the working sound of the return pump
relay and return pump.
The circuit is normal if the working sound of the return
pump relay and return pump are made in accordance
with Tech2’s instruction.

060L300002

8A-20 ELECTRICAL-BODY AND CHASSIS

Caution:
Never push or tow the vehicle in an attempt to start it.
Extensive damage to the emission system and other
vehicle parts will result.
(Only catalytic converter vehicle)
Treat both the discharged battery and the booster battery
with great care when using jumper cables.
Carefully follow the procedure outlined below.
Always be aware of the dangers of sparking.
Failure to follow the following procedure can result in:
a. Serious personal injury, specially to your eyes.
b. Extensive property damage from a battery explosion,
battery acid discharge, or electrical file.
c. Extensive damage to the electronic components o
f
both vehicles.
Do not use a 24 volt booster battery.
Serious damage to the vehicle's electrical system and
electronic components will result.

Jump Starting Procedure
1. Set the parking brake on both vehicles.
2. If one or both vehicles is equipped with a manual
transmission, place the gear shift in the "NEUTRAL"
position.
3. Turn off the ignition on both vehicles.
4. Turn off all vehicle lights and accessories.
5 Be sure that the two vehicles are not touching.

Attach the end of one jumper cable to the booster battery
positive terminal.
6
Attach the other end of the same cable to the discharged
battery positive terminal.
7. Once again, check that the booster battery has a 12 vol
t
rating.
8.
Attach one end of the remaining booster cable to the
booster battery negative terminal.
9.
Attach the other end of the booster cable to a solid ground
(such as the air conditioner compressor mounting bracke
t
or the alternator mounting bracket) in the engine room o
f
the vehicle with the discharged battery.
Be sure that the ground connection is at least 500 mm (20
in) from the discharged battery.

ELECTRICAL-BODY AND CHASSIS 8A-25
Light Name Rated Power
V-W Number of
Bulbs Lens
Color Remarks
W/O Tacho 5Illumination light 14-2
W/ Tacho 7White
Turn Signal 14-1.12 2 Green
High Beam 14-1.12 1 Blue
Low Fuel 14-1.12 1 Amber
A/T Oil Temp 14-1.12 1 Red
Brake system 14-1.12 1 Red
4WD 14-1.12 1 Green
Seat belt 14-1.12 1 Red
Oil pressure 14-1.12 1 Red
ABS 14-1.12 1 Amber
SEDIMENTER 14-1.12 1 Red
AIR BAG 14-1.12 1 Red
Brake 14-1.12 1 Red
Charge 14-1.12 1 Red
Check Trans 14-1.12 1 Red
Check 4WD 14-1.12 1 Red
Power drive 14-1.12 1 Amber
3rd start 14-1.12 1 Green
4L 14-1.12 1 Green
Cruise Set 14-1.12 1 Green
Check Engine 14-1.12 1 Amber
Front Fog 14-1.12 1 Green
Rear foglight 14-1. 12 1 Amber
Glow 14-1.12 1 Amber
P LED 1 Green
R LED 1 Green
N LED 1 Green
D LED 1 Green
3 LED 1 Green
2 LED 1 Green












Indicator/
Warning
light
A/T shift
indicator
L LED 1 Green

8A-212 ELECTRICAL-BODY AND CHASSIS
Windshield Washer Spray
Be sure that the engine hood is completely closed before
checking the windshield washer spray adjustment.
Windshield Washer Spray Position: Refer to the illustration.

RTW38DSF000201



Connector
Be absolutely sure that the wiper motor connector is securely
connected.
This will prevent a poor contact and an open circuit.


Note:
Windshield wiper arm and blade assembly configurations
are different for the right-hand and left-hand side of the
vehicle.
Be careful not to confuse the right-hand and left-hand side
assemblies.



This illustration is based on RHD model
WASHER TANK MOTOR
Removal
1. Remove the head light.

Refer to the head light in this manual.
2. Remove the inner riner.
3. Pull out the clip washer filler.
4. Remove the washer tank nuts.

ELECTRICAL-BODY AND CHASSIS 8A-261
2. Even when the parking brake lever is pulled, the indicator light does not go off

Checkpoint Trouble Cause Countermeasure

Adjust the SW. installation
position or replace the parking
brake SW. Incorrect the parking brake
SW. adjustment or brake SW.
faulty
NG Thermo unit malfunction
Replace the brake fluid level
SW., or vacuum SW., or
repair a short circuit between
the parking brake SW.
connector 1
C-39
(Lever: 1
R-4) and 9 B-23
or the brake fluid level SW.
connector 2
C-37 and 9
B-23, (or the vacuum SW.
connector 1
C-38 and 9
B-23 : 4JH1-TC ONLY)
Check to see if the indicator
light goes off when the parking
brake SW. connector 1
C-39
(Lever: 1
R-4) is
di t d
Brake fluid level SW. or
vacuum SW. faulty or short
circuit
NG OK

Parking brake SW. installation
position and function




3. Oil pressure warning light does not go off while engine is running


Refer to ENGINE Section

Refer to ENGINE Section
NG Thermo unit malfunction

Repair a short circuit between
1
E-1 and 3 B-24

Check to see the warning light
goes off when the oil pressure
SW. connector
1
E-1 is disconnected


Short circuit


Replace the oil pressure unit
(or the oil pressure SW.)
Continuity between the oil
pressure SW. connector
1
E-1 and the body ground
when the engine is operating


Oil pressure unit (or oil
pressure SW) faulty
NG NG OK
OK

Engine oil pressure

8A-278 ELECTRICAL-BODY AND CHASSIS
Low Fuel Indicator Light Inspection
1. Disconnect the fuel tank unit wire connector.
2. Turn the key switch on. Check that the bulb lights.
If operation is not correct, remove and check the bulb or circuit.
or If check whether low fuel turns on fuel input (B-24) at the
time of open and key on.
 meter is check at low fuel
140R300006





Check level sensor operation
1. Remove the fuel tank unit.
2.
Apply battery voltage between terminal (B) and (C) through
a 1.12 watt bulb. Check that the bulb lights.
Note:
It will take a short time for the bulb light.
3. Submerge the sensor in fuel. Check that the bulb goes out.
If operation is not correct, replace the fuel tank unit.

BRAKE SYSTEM WARNING LIGHT
The brake system warning light comes on while the parking
brake is set and the engine run position.
Note:
The parking brake indicator light circuit is designed to
prevent driving of the vehicle with the parking brake on.
It does not indicate the condition of the parking brake
system.



The parking brake switch is in parallel with the brake fluid
switch.



The brake system warning light also comes on when reservoir
brake fluid level falls below the specified limit with the parking
brake released and the engine run position.

6A – 24 ENGINE MECHANICAL

SERVICING
Servicing refers to general maintenance procedures to be performed by qualified service personnel.



RTW36ASH000401
MODEL IDENTIFICATION
Engine Serial Number
The engine number is stamped on the rear left hand side
of the cylinder body.
The engine number is stamped in the plate in front of the
engine room as well.


AIR CLEANER
Element cleaning procedures will vary according to the
condition of the element.

Dust Fouled Element
Rotate the element with your hand while applying
compressed air to the inside of the element. This will blow
the dust free.
Compressed air pressure kPa (kg/cm
2 /psi)
392 – 490 (4 – 5/57 – 71)


LUBRICATING SYSTEM
Main Oil Filter (Cartridge Type Paper Element)
Replacement Procedure
1. Drain the engine oil.
2. Retighten the drain plug.
3. Loosen the used oil filter by turning it counterclockwise
with a filter wrench.
Filter Wrench: 5-8840-0200-0


RTW36ASH000101


4. Clean the oil cooler fitting face. This will allow the new
oil filter to seat properly.
5. Apply a light coat of engine oil to the filter O-ring.
6. Turn in the new oil filter until the filter O-ring is fitted
against the sealing face.
7. Use the filter wrench to turn in the filter an additional
2/3 turns.
8. Check the engine oil level and replenish to the
specified level if required.
130RY00003
6A-6

ENGINE MECHANICAL 6A – 25
Replenished Engine Oil MAX lit (US/UK gal)
Condition


Model Engine Dry
With oil filter
replacement Without oil
filter
replacement
4
2
4
4
(4JA1L/TC)6.2 (1.64/1.36) 5.2  4.2
(1.37  1.11
/ 1.14  0.92) 4.5  3.5
(1.19  0.93
/ 0.99  0.77)
4
2
(4JH1TC)
6.2 (1.64/1.36) 5.2  4.2
(1.37  1.11
/ 1.14  0.92) 4.5  3.5
(1.19  0.93
/ 0.99  0.77)
4
4
(4JH1TC) 7.0 (1.85/1.54) 6.2  5.2
(1.64  1.37
/ 1.36  1.14) 5.3  4.3
(1.72  1.14
/ 1.17  0.95)

9. Start the engine and check for oil leakage from the
main oil filter.
6A-7




FUEL SYSTEM
Fuel Filter Replacement Procedure
1. Remove the fuel filter by turning it counterclockwise
with a filter wrench.
Filter Wrench: 5-8840-0253-0 (J-22700)
Note:
Be careful not to spill the fuel in the filter cartridge.






RTW46ASH000501








2. Clean the fuel filter cartridge fitting faces.
This will allow the new fuel filter to seat properly
3. Apply a light coat of engine oil to the O-ring.
4. Turn in the fuel filter until the sealing face comes in
contact with the O-ring.
5. Turn in the fuel filter an additional 2/3 of a turn with a
filter wrench.
Filter Wrench : 5-8840-0253-0 (J-22700)





6. Operate the priming pump until the air discharged
completely from fuel system.
7. Start the engine and check for fuel leakage.
Note:
The use of an ISUZU genuine fuel filter is strongly
recommended.
041RY00009

6A – 26 ENGINE MECHANICAL



041RY00011
Draining Procedure
The indicator light will come on when the water level in the
water separator exceeds the specified level.
Drain the water and foreign material from the water
separator (inside chassis frame) with the following
procedure.





1. Place the drain pan under the drain plug.
2. Loosen the drain plug and drain water.
3. After draining the water, tighten the drain plug.
4. Operate the priming pump on the fuel filter several
times and check for fuel leakage.
5. Check the water separator indicator light. It should be
off.



Except EURO III model
RTW46ASH002901




For EURO III model
RTW46ASH000501


Air Bleeding
1. Operate the priming pump until strong resistance is
felt.
2. Wait 1 minute, and operate the priming pump until
strong resistance is felt.
3. Once more wait, and operate the priming pump until
strong resistance is felt.
4. Turn the ignition switch to the "ON" position. Wait until
the glow indicator lamp turns off.
5. Turn the ignition switch to the "START" position and
crank the engine until it starts.
6. If the engine does not start, repeat Step 3 - 5.
7. Allow the engine to idle for 3 minutes to bleed air
completely form the fuel system and check for fuel
leakage.
Note:
Insufficient air bleeding may cause the Diagnostic
Trouble Code (DTC) store or improper engine
performance.