switch ISUZU TF SERIES 2004 Workshop Manual

ENGINE DRIVEABILITY AND EMISSIONS 6E–103
FUEL SYSTEM ELECTRICAL TEST
Circuit Description
When the ignition switch is first turned ON, the engine
control module (ECM) energizes the fuel pump relay
which applies power to the in-tank fuel pump. The fuel
pump relay will remain ON as long as the engine is
running or cranking and the ECM is receiving 58X
crankshaft position pulses. If no 58X crankshaft position
pulses are present, the ECM de-energizes the fuel
pump relay within 2 seconds after the ignition is turned
ON or the engine is stopped.
The fuel pump delivers fuel to the fuel rail and injectors,
then to the fuel pressure regulator. The fuel pressure
regulator controls fuel pressure by allowing ex cess fuel
to be returned to the fuel tank. With the engine stopped
and ignition ON, the fuel pump can be turned ON by
using a command by the scan tool.
Diagnostic Aids
An intermittent may be caused by a poor connection,
rubbed-through wire insulation, or a wire broken inside
the insulation. Check for the following items:
Poor connection or damaged harness - Inspect the
ECM harness and connectors for improper mating,
broken locks, improperly formed or damaged
terminals, poor terminal-to-wire connection, and
damaged harness.
Caution: To reduce the risk of fire and personal
injury:
It is necessary to relieve fuel system pressure
before connecting a fuel pressure gauge.
Refer to Fuel Pressure Relief Procedure,
below.
A small amount of fuel may be released when
disconnecting the fuel lines. Cover fuel line
fittings with a shop towel before
disconnecting, to catch any fuel that may leak
out. Place the towel in an approved container
when the disconnect is completed.

6E–108 ENGINE DRIVEABILITY AND EMISSIONS
FUEL SYSTEM DIAGNOSIS
Circuit Description
When the ignition switch is turned ON, the engine
control module (ECM) will turn ON the in-tank fuel
pump. The in-tank fuel pump will remain ON as long as
the engine is cranking or running and the ECM is
receiving 58X crankshaft position pulses. If there are no
58X crankshaft position pulses, the ECM will turn the in-
tank fuel pump OFF 2 seconds after the ignition switch
is turned ON or 2 seconds after the engine stops
running.
The in-tank fuel pump is an electric pump within an
integral reservoir. The in-tank fuel pump supplies fuel
through an in-line fuel filter to the fuel rail assembly. The
fuel pump is designed to provide fuel at a pressure
above the pressure needed by the fuel injectors. A fuel
pressure regulator, attached to the fuel rail, keeps the
fuel available to the fuel injectors at a regulated
pressure. Unused fuel is returned to the fuel tank by a
separate fuel return line.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Connect the fuel pressure gauge to the fuel feed line
as shown in the fuel system illustration. Wrap a shop
towel around the fuel pressure connection in order to
absorb any duel leakage that may occur when
installing the fuel pressure gauge. With the ignition
switch ON and the fuel pump running, the fuel
pressure indicated by the fuel pressure gauge
should be 283-376 kPa (41-55 psi). This pressure is
controlled by the amount of pressure the spring
inside the fuel pressure regulator can provide.
3. A fuel system that cannot maintain a constant fuel
pressure has a leak in one or more of the following
areas:
The fuel pump check valve.
The fuel pump flex line.
The valve or valve seat within the fuel pressure
regulator.

ENGINE DRIVEABILITY AND EMISSIONS 6E–261
DIESELING, RUN-ON SYMPTOM
DEFINITIONS: Engine continues to run after key is turned OFF, but runs very rough. If engine runs smoothly, check
the ignition switch and adjustment.
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?—Go to Step 2Go to OBD
System Check
2 1. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?—Verify repair Go to Step 3
3 Was a visual/physical check performed?
—Go to Step 4Go to Visual /
physical Check.
4 Check for a short between battery voltage and the
ignition feed circuit.
Was a problem found?—Verify repair Go to Step 5
5 Check the fuel leaking from injector. Refer to Fuel
System Diagnostic.
Was the problem found?—Verify repair Go to Step 6
6 1. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
followi ng:
Visual/physical inspection
Te c h 2 d a t a
All electrical connections within a suspected
circuit and/or system
Was a problem found?—Verify repair Go to Step 7
7 Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved?—Verify repair Go to Step 8
8 Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure.—Veri fy repai r—

6E–268 ENGINE DRIVEABILITY AND EMISSIONS
KNOCK SENSOR
Location
Right-hand side of the cylinder block.
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the knock sensor connector.
3. Loosen a bolt and remove knock sensor from the
cylinder block.
Installation Procedure
1. Tighten the knock sensor by a bolt with specified
tightening torque.
Tightening Torque
Bolt: 20N·m (2.0kgf·m)
2. Connect a knock sensor connector to the knock
sensor.
3. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.
POWER STEERING PRESSURE (PSP)
SWITCH
Location
Installed on the power steering pump assembly.
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the power steering pressure switch
connector.
3. Loosen and remove the power steering pressure
switch from the power steering pump.
Installation Procedure
1. Install the power steering pressure switch to the
power steering pump.
2. Tighten the power steering pressure switch.
3. Connect a connector to the power steering pressure
switch.
4. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.
Verify no power steering fluid leaking from the sensor
threads after replacement.

ENGINE DRIVEABILITY AND EMISSIONS 6E–277
SPARK PLUG CABLES
The cable contains a synthetic conductor which is easily
damaged. Never stretch or kink the cable. Disconnect
the cable from spark plug and the ignition coil.
The original equipment cables and the ignition coil are
marked to show correct location of the cables. If spark
plug cables or the ignition coil are replaced previously,
before cables are removed from the ignition coil, mark
the cables and the coil so they can be reconnected in
the same position.
Inspection
NOTE: Never puncture the spark plug cable’s insulation
with a needle or the pointed end of a probe into the
cable. An increase in resistance would be created which
would cause the cable to become defective.
1. If the cable has broken or cracked insulation, it must
be replaced.
2. If the terminals are corroded or loose, the cable
must be replaced.
3. Check that the cable resistance does not ex ceed
specified value.
#1 cylinder: 3.50k
- 5.24k

#2 cylinder: 2.89k
- 4.33k

#3 cylinder: 2.49k
- 3.73k

#4 cylinder: 2.22k
- 3.32k

EMISSION CONTROL ;




CO ADJUSTER (W/
O CATALYSTIC CONVERTER)
CO : Carbon monox ide
Location
Under the leht-hand side of the front sheet.
Removal Procedure
1. Remove the left-hand side of the front sheet. Refer
to Sec.10 CAB “Front Sheet”.
2. Disconnect the CO adjuster connector.
3. Remove the CO adjuster.
Installation Procedure
1. Connect the CO adjuster connector.
2. Install the left-hand side of the front sheet. Refer to
Sec.10 CAB “Front Sheet”.
3. Check and adjust CO concentration.
Checking procedure
1. Operate the engine at normal temperature.
2. Turn all accessories switch OFF.
3. Place the select lever in the “N” range.
4. Start the engine at idle.

6E–278 ENGINE DRIVEABILITY AND EMISSIONS
5. Measure the CO concentration for 1-3 minutes, after
idlling the engine to allow the CO concentration to
stabilize.
6. Check the CO concentration.
7. If the value is not within specification, adjust the CO
concentration.A djustment Procedure
1. Warm-up the engine.
2. Turn OFF switches of all electrical equipment.
3. Open the CO adjuster cap.
4. Turn the CO adjuster screw checking the CO
concentration
.
5. Adjust the CO concentration within specification.
Specification:
CO concentration : 0.6 1.0 %
NOTE: Apply the liquid gasket to the CO adjuster screw
after the adjustment.

6G-4 ENGINE LUBRICATION
Oil Pump
Oil Pump and Associated Parts
Legend
1 Oil Pump Assembly
2 Oil Pressure Switch3 Gasket
4 Sleeve



Disassembly
1. Remove crankshaft timing pulley.
2. Remove oil pan.
3. Remove oil strainer.
4. Remove oil pump assembly.
5. Remove oil pressure switch.
6. Remove gasket.
7. Remove sleeve.

ENGINE LUBRICATION 6G-5

Inspection and Repair
CAUTION: Make necessary correction or parts
replacement if wear, damage or any other abnormal
conditions are found through inspection.
Body and Gears
The pump assembly must be replaced if one or more of the
conditions below is discovered during inspection:
Indentation of gear pair - Use feeler strip and straight edge.
Dimension: 0.03 mm to 0.10 mm
(0.0012 to 0.0039 in)



Oil Strainer
Check the oil strainer for cracking and scoring. If cracking and
scoring are found, the oil strainer must be replaced.




Reassembly
1. Install oil pressure switch to the oil pump.
Torque: 40 N




m (4.1 kgf




m)
2. Install the oil pump with the sleeve and the gasket.
Torque: 6 N




m (0.6 kgf




m)
3. Install oil strainer.
Torque: 8 N




m (0.8 kgf




m)
4. Install the oil pan.
Tighten the bolts:
15 N




m (1.5 kgf




m)
5. Install crankshaft timing pulley.
Tighten the bolts:
20 N




m (2.0 kgf




m)

6G-6 ENGINE LUBRICATION
Oil Pan
Oil Pan and Associated Parts
(2.4L 4 ×4 Model)
(2.4L 4 ×2 Model)






Important
Disassembly
1. Loosen a drain plug to drain oil.
2. Remove engine hood.
3. Remove engine rear mounting.
4. Remove transmission assembly.
5. Remove engine front mounting.
6. Raise the vehicle and support with switch stands, and then remove engine.
7. Remove oil pan.

HEATER AND AIR CONDITIONING 1-3
GENERAL DESCRIPTION
SYSTEM COOLING LINE










1.
Compressor 8.
Evaporator core
2.
Magnetic clutch 9.
Blower motor
3.
Receiver/Drier 10.
Heater unit
4.
Dual pressure switch or Trinary 11.
Mode (DEF/FOOT) control door

pressure switch (4J

-TC, 6VE1, 12.
Mode (VENT) control door
C24SE) 13.
Electronic thermostat
5.
Condenser 14.
Heater core
6.
Evaporator assembly
7.
Expansion valve

RTW310LF001001