2004 ISUZU TF SERIES fuel type

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-227
Condition For Setting The DTC and Action Taken When The DTC Sets
Flash
Code Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0201 A Injector 1 Control
Circuit
P0202 A Injector 2 Control
Circuit
P0203 A Injector 3 Control
Circuit
P0204 A Injector 4 Control
Circuit
P0205 A Injector 5 Control
Circuit
31
P0206 A Injector 6 Control
Circuit 1. No DTC relating to CMP sensor and CKP sensor.
2. Under sequential injection.
3. Injection pulse is between 2.5ms and 7.5 ms.
4. Except fuel cut operation.
5. Engine speed is between 600rpm and 2000rpm.
6. 30 injection signals are not detected consecutively. No fail-safe function.

CIRCUIT DESCRIPTION
The Engine Control Module ECM has six individual
injector driver circuits. Each controls an injector. When
a driver circuit is grounded by the (ECM), the injector is
activated. The ECM monitors the current in each drive
r
circuit. The voltage on each driver is monitored to detect
a fault. If the voltage is not what the ECM expects to
monitor on the circuit, a DTC is set. This DTC is also
set if an injector driver is shorted to voltage or if there is
an open circuit.

DIAGNOSTIC AIDS
An injector driver circuit that is open or shorted to
voltage will cause a DTC P0201, P0202, P0203, P0204,
P0205 or P0206 to set. It will also cause a misfire due
to an inoperative injector.
Long term and short term fuel trims that are excessively
high or low are a good indication that an injector is
faulty.

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-243
DIAGNOSTIC TROUBLE CODE (DTC) P0341(FLASH CODE 41) CAMSHAFT
POSITION SENSOR CIRCUIT RANGE/PERFORMANCE
DIAGNOSTIC TROUBLE CODE (DTC) P0342 (FLASH CODE 41) CAMSHAFT
POSITION SENSOR CIRCUIT NO SIGNAL



RUW46EMF000101

Condition For Setting The DTC and Action Taken When The DTC Sets
Flash
Code Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0341 B Camshaft Position
Sensor Circuit
Range/Performance 1. Engine speed below 2000rpm.
2. No crankshaft position sensor DTC P0336 or P0337.
3. Incorrect pulse is detected consecutively. 41

P0342 B Camshaft Position
Sensor Circuit No
Signal 1. No DTC relating to CKP sensor.
2. Engine speed is below 2000rpm.
3. No pulse is detected consecutively. Fuel cut is operated at high engine
speed.

6E-250 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Condition For Setting The DTC and Action Taken When The DTC Sets
Flash
Code Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0351 A Ignition 1 Control
Circuit
P0352 A Ignition 2 Control
Circuit
P0353 A Ignition 3 Control
Circuit
P0354 A Ignition 4 Control
Circuit
P0355 A Ignition 5 Control
Circuit
42
P0356 A Ignition 6 Control
Circuit 1. No DTC relating to CMP sensor and CKP sensor.
2. Engine speed is between 250rpm and 850 rpm.
3. 10 ignition signals are not detected consecutively. Fuel cut is operated more than
2000rpm.

CIRCUIT DESCRIPTION
The Engine Control Module's (ECM) control circuit 1
provides a zero-volt or a 5-volt output signal to the
ignition coil. The normal voltage on the circuit is zero
volts. When the ignition coil receives the 5-volt signal
from the ECM, it provides a ground path for the B+
supply to the primary side of the number 1 ignition coil.
When the ECM shuts off the 5 volts to the ignition coil,
the ignition coil turns “OFF." This causes the ignition coil
primary magnetic field to collapse, producing a voltage
in the secondary coil which fires the spark plug.
The circuit between the ECM and ignition coil is
monitored for an open circuit, short to voltage, and shor
t
to ground. When the ECM detects a problem on ignition
control circuit, it will set a DTC P0351, P0352, P0353,
P0354, P0355 or P0356.

DIAGNOSTIC AIDS
Check for the following conditions:
 Poor connection at ECM – Inspect the harness
connectors for backed-out terminals, imprope
r
mating, broken locks, improperly formed or damaged
terminals, and poor terminal-to-wire connections.
 Damaged harness –Inspect the wiring harness fo
r
damage. If the harness appears to be OK, observe
the Tech 2 display related to DTC P0351 or P0352,
P0353, P0354, P0355 or P0356 while moving the
connector and wiring related to the ignition system.
A
change in the display will indicate the location of the
fault.
Reviewing the Failure Records vehicle mileage since
the diagnostic test last failed may help determine ho
w
often the condition that caused the DTC to be set
occurs. This may assist in diagnosing the condition.

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-279
DIAGNOSTIC TROUBLE CODE (DTC) P0500 (FLASH CODE 24) VEHICLE
SPEED SENSOR (VSS) CIRCUIT RANGE/PERFORMANCE



RTW46EMF000301

Condition For Setting The DTC and Action Taken When The DTC Sets
Flash
Code Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
24 P0500 B Vehicle Speed Sensor
Circuit
Range/Performance 1. Engine speed is below 5000rpm.
2. Under fuel cut operation.
3. Vehicle speed sensor output is below 1km/h.
Above conditions are met for 4 seconds. The ECM use 10km/h condition as
substitute.


CIRCUIT DESCRIPTION
The vehicle speed sensor has a magnet rotated by the
transmission output shaft. Attached to the sensor is a
hall effect circuit the interacts with the magnetic field
treated by the rotating magnet. A 12-volt operating
supply for the speed sensor hall circuit is supplied from
the meter fuse. The VSS pulses to ground the 9-vol
t
signal sent from the Engine Control Module (ECM) on
the reference circuit. The ECM interprets vehicle speed
by the number of pulses to ground per second on the
reference circuit.

DIAGNOSTIC AIDS
An intermittent may be caused by a poor connection,
rubbed–through wire insulation or a wire broken inside
the insulation. Check for:
 Poor connection —Inspect the ECM harness and
connectors for improper mating, broken locks,
improperly formed or damaged terminals, and poo
r
terminal-to-wire connection.
 Damaged harness —Inspect the wiring harness fo
r
damage.

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-297
Condition For Setting The DTC and Action Taken When The DTC Sets
Flash
Code Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P1508 B Idle Air Control System
Low/Closed 1. No DTC relating to MAF sensor, IAT sensor, ECT sensor,
TPS, CMP sensor, CKP sensor, VSS and system voltage.
2. Engine speed is between 675rpm and 6000rpm.
3. Engine coolant temperature is more than 75
C.
4. Intake air temperature is between -10
C and 80
C.
5. Vehicle is stopping.
6. Small amount of intake air through the idle air control
valve. (Idle air control valve is sticking at close position.)
Above conditions are met for 2 seconds. 22
P1509 B Idle Air Control System
High/Open 1. No DTC relating to MAF sensor, IAT sensor, ECT sensor,
TPS, CMP sensor, CKP sensor, VSS and system voltage.
2. Engine speed is between 675rpm and 6000rpm.
3. Engine coolant temperature more than 75
C.
4. Intake air temperature is between -10
C and 80
C.
5. Vehicle is stopping.
6. Large amount of intake air through the idle air control
valve. (Idle air control valve is sticking at open position.)
Above conditions are met for 2 seconds. Fuel cut is operated at high idle
speed.

CIRCUIT DESCRIPTION
The engine control module (ECM) controls engine idle
speed by adjusting the position of the idle air control
(IAC) motor pintle. The IAC is a bi-directional steppe
r
motor driven by two coils. The ECM applies current to
the IAC coils in steps (counts) to extend the IAC pintle
into a passage in the throttle body to decrease air flow.
The ECM reverses the current to retract the pintle,
increasing air flow. This method allows highly accurate
control of idle speed and quick response to changes in
engine load. If the ECM detects a condition where too
low of an idle speed is present and the ECM is unable
to adjust idle speed by increasing the IAC counts, DTC
P1508 or P1509 will set, indicating a problem with the
idle control system.

DIAGNOSTIC AIDS
Check for the following conditions:
 Poor connection at ECM or IAC motor –Inspec
t
harness connectors for backed-out terminals,
improper mating, broken locks, improperly formed o
r
damaged terminals, and poor terminal-to-wire
connection.
 Damaged harness – Inspect the wiring for damage.
 Restricted air intake system – Check for a possible
collapsed air intake duct, restricted air filter element,
or foreign objects blocking the air intake system.

6E-374 3.5L ENGINE DRIVEABILITY AND EMISSIONS
FUEL PRESSURE RELIEF
Caution:
To reduce the risk of the fire and personal injury, it
is necessary to relive the fuel system pressure
before servicing the fuel system components.
Caution:
After relieving the fuel system pressure, a small
amount of fuel may be released when servicing fuel
lines or connections. Reduce the chance o
f
personal injury by covering the fuel line fitting with
a short towel before disconnecting the fittings. The
towel will absorb any fuel that may leak out. When
the disconnect is completed, place the towel in an
approved container.

1. Remove the fuel filler cap.
2. Remove the fuel pump relay.
3. Start the engine and allow it to stall.
4. Crank the engine for about 30 seconds.
5. Disconnect the negative battery cable.



FUEL RAIL ASSEMBLY

Removal Procedure
NOTE:
 Do not attempt to remove the fuel inlet fitting on
the fuel rail. It is staked in place. Removing the
fuel inlet fitting will result in damage to the fuel
rail or the internal O-ring seal.
 Use care when removing the fuel rail assembly in
order to prevent damage to the injector electrical
connector terminals and the injector spray tips.
 Fittings should be capped and holes plugged
during servicing to prevent dirt and othe
r
contaminants from entering open lines and
passages.
Important: Before removal, the fuel rail assembly may
be cleaned with a spray type engine cleaner. Follow the
spray package instructions. Do not immerse the fuel
rails in liquid cleaning solvent.
1. Depressurize the fuel system. Refer to Fuel
Pressure Relief Procedure in this Section.
2. Disconnect the negative battery cable.
3. Remove the engine cover.
4. Disconnect the accelerator pedal cable from throttle
body and cable bracket.

5. Disconnect the connectors from, solenoid valve,
sensing valve.
6. Disconnect the vacuum hose on canister solenoid
and positive crankcase ventilation hose.
7. Remove the common chamber Refer to the
common chamber in Engine Mechanical.
1. Lift up carefully on the fuel injectors. Do no
t
separate the fuel injectors from the fuel rail.
2. If an injector becomes separated from the fuel
rail, the infector O-ring seals and the retaine
r
clip must be replaced.
3. Drain residual fuel into an approved container.




060RW044
8. If removal of the fuel pressure regulator is
necessary, refer to Fuel Pressure Regulator.
9. If removal of the fuel injectors is necessary, refer to
Fuel Injectors.

Installation Procedure
1. If the fuel injectors were removed, install them.
Refer to Fuel Injectors.
2. If the fuel pressure regulator was removed, install
it. Refer to Fuel Pressure Regulator.

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-375
3. Install the common chamber. Refer to common
chamber in engine Mechanical.




060RW044
4. Connect the vacuum hose on Canister Solenoid
and positive crankcase ventilation hose.
5. Connect the connectors to, solenoid valve.
6. Connect the accelerator pedal cable to throttle
body and cable bracket.
7. Install the engine cover.
8. Connect the negative battery cable.
9. Crank the engine until it starts. Cranking the
engine may take longer than usual due to trapped
air in the fuel rail and in the injectors.

FUEL INJECTORS

Removal Procedure
NOTE: If the fuel injectors are leaking, the engine oil
may be contaminated with fuel. Check the oil fo
r
signs of contamination and change the oil and the
filter if necessary.
NOTE: Use care in removing the fuel injectors in
order to prevent damage to the fuel injecto
r
electrical connector pins or the fuel injector
nozzles. The fuel injector is an electrical component
and should not be immersed in any type of cleane
r
as this may damage the fuel injector.
Important: Fuel injectors are serviced as a complete
assembly only.
1. Disconnect the negative battery cable.
2. Remove the upper intake manifold. Refer to
Common Chamber in Engine Mechanical..
3. Remove the fuel rail. Refer to Fuel Rail.




060RW044

6E-380 3.5L ENGINE DRIVEABILITY AND EMISSIONS
SPARK PLUGS

Removal Procedure
1. Remove spark plugs.

Inspection Procedure
The spark plug affects entire engine performance and
therefore its inspection is very important.
 Check electrode and insulator for presence o
f
cracks, and replace if any.
 Check electrode for wear, and replace if necessary.
 Check gasket for damage, and replace if necessary.
 Measure insulation resistance with an ohmmeter,
and replace if faulty.
 Adjust spark plug gap to 1.0 mm (0.04 in)

1.1 mm
(0.043 in).
 Check fuel and electrical systems if spark plug is
extremely dirty.
 Use spark plugs having low heat value (hot type
plug) if fuel and electrical systems are normal.
 Use spark plugs having high heat value (cold type
plug) if insulator and electrode are extremely
burned.
Sooty Spark Plugs
Much deposit of carbon or oil on the electrode and
insulator of spark plug reduces the engine performance.
Possible causes:
 Too rich mixture
 Presence of oil in combustion chamber
 Incorrectly adjusted spark plug gap
Burning Electrodes
This fault is characterized by scorched or heavily
oxidized electrode or blistered insulator nose.
Possible causes:
 Too lean mixture
 Improper heat value

Measuring Insulation Resistance
 Measure insulation resistance using a 500 volt
megaohm meter.
 Replace spark plugs if measured value is out o
f
standard.
Insulation resistance: 50 M
  or more




011RS010
Cleaning Spark Plugs
 Clean spark plugs with a spark plug cleaner.
 Raise the ground electrode to an angle of 45 to 60
degrees. If electrode is wet, dry it before cleaning.

After spark plug is thoroughly cleaned, check
insulator for presence of cracks.
 Clean threads and metal body with a wire brush.
 File the electrode tip if electrode is extremely worn.