2004 ISUZU TF SERIES change time

6E-150 3.5L ENGINE DRIVEABILITY AND EMISSIONS
CIRCUIT DESCRIPTION
The mass air flow (MAF) sensor measures the amount
of air which passes through it into the engine during a
given time. The Engine Control Module (ECM) uses the
mass air flow information to monitor engine operating
conditions for fuel delivery calculations. A large quantity
of air entering the engine indicates an acceleration o
r
high load situation, while a small quantity of air indicates
deceleration or idle.
The MAF sensor produces a frequency signal which
can be monitored using a Tech 2. The frequency will
vary within a range of around 5 to 8 g/s at idle to around
25 to 40 g/s at maximum engine load. DTC P0102 will
be set if the signal from the MAF sensor is below the
possible range of a normally operating MAF sensor.
.

DIAGNOSTIC AIDS
Check for the following conditions:
 Poor connection at ECM – Inspect harness
connectors for backed-out terminals, imprope
r
mating, broken locks, improperly formed or damaged
terminals, and poor terminal-to-wire connection.
 Misrouted harness – Inspect the MAF senso
r
harness to ensure that it is not routed too close to
high voltage wires.
 Damaged harness –Inspect the wiring harness fo
r
damage. If the harness appears to be OK, observe
the Tech 2 while moving connectors and wiring
harnesses related to the MAF sensor. A change in
the display will indicate the location of the fault.
If DTC P0102 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set


Diagnostic Trouble Code (DTC) P0102 (Flash Code 61) Mass Air Flow Sensor
Circuit Low Input
Step Action Value (s) Yes No
1
Was the "On-Board Diagnostic (OBD) System Check"
performed?
- Go to Step 2 Go to On Board
Diagnostic (OBD)
System Check
2
1. Connect the Tech 2.
2. Review and record the failure information.
3. Select "F0: Read DTC Infor By Priority" in "F0:
Diagnostic Trouble Code".
Is the DTC P0102 stored as "Present Failure"?
- Go to Step 3 Refer to
Diagnostic Aids
and Go to Step 3
3
1. Using the Tech2, ignition "On" and engine "Off".
2. Select "Clear DTC Information" with the Tech2 and
clear the DTC information.
3. Operate the vehicle and monitor the "F5: Failed
This Ignition" in "F2: DTC Information"
Was the DTC P0102 stored in this ignition cycle?
- Go to Step 4 Refer to
Diagnostic Aids
and Go to Step 4

6E-168 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0117 (FLASH CODE 14) ENGINE
COOLANT TEMPERATURE (ECT) SENSOR LOW INPUT



RUW46EMF000201

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)
14 P0117 A Engine Coolant
Temperature Sensor
Low Input
ECT sensor output voltage is below 0.08V. The ECM uses default engine
coolant temperature value based on
start-up ECT and time from start.

Circuit Description
The engine coolant temperature (ECT) sensor is a
thermistor mounted on a coolant crossover pipe at the
rear of the engine. The Engine Control Module (ECM)
applies a voltage (about 5 volts) through a pull-up
resistor to the ECT signal circuit. When the engine
coolant is cold, the sensor (thermistor) resistance is
high, therefore the ECM will measure a high signal
voltage. As the engine coolant warms, the senso
r
resistance becomes lower, and the ECT signal voltage
measured at the ECM drops.

DIAGNOSTIC AIDS
Check for the following conditions:
 Poor connection at ECM – Inspect harness
connectors for backed-out terminals, imprope
r
mating, broken locks, improperly formed or damaged
terminals, and poor terminal-to-wire connection.
 Damaged harness –Inspect the wiring harness fo
r
damage. If the harness appears to be OK, observe
the ECT display on the Tech 2 while moving
connectors and wiring harnesses related to the ECT
sensor. A change in the ECT display will indicate the
location of the fault.
If DTC P0117 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
If it is determined that the DTC occurs intermittently.

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-173
DIAGNOSTIC TROUBLE CODE (DTC) P0118 (FLASH CODE 14) ENGINE
COOLANT TEMPERATURE (ECT) SENSOR HIGH INPUT



RUW46EMF000201

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)
14 P0118 A Engine Coolant
Temperature Sensor
High Input ECT sensor output voltage is more than 4.8V. The ECM uses default engine
coolant temperature value based on
start-up ECT and time from start.

CIRCUIT DESCRIPTION
The engine coolant temperature (ECT) sensor is a
thermistor mounted in on a coolant crossover pipe a
t
the rear of the engine. The Engine Control Module
(ECM) applies a voltage (about 5 volts) through a
pull-up resistor to the ECT signal circuit. When the
engine coolant is cold, the sensor (thermistor)
resistance is high, therefore the ECM will measure a
high signal voltage. As the engine coolant warms, the
sensor resistance becomes less, and the ECT signal
voltage measured at the ECM drops.

DIAGNOSTIC AIDS
Check for the following conditions:
 Poor connection at ECM – Inspect harness
connectors for backed-out terminals, imprope
r
mating, broken locks, improperly formed or damaged
terminals, and poor terminal-to-wire connection.
 Damaged harness – Inspect the wiring harness fo
r
damage. If the harness appears to be OK, observe
the ECT display on the Tech 2 while moving
connectors and wiring harnesses related to the ECT
sensor. A change in the ECT display will indicate the
location of the fault.
If DTC P0118 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.

6E-202 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)
P0132 A O2 Sensor Circuit High
Voltage (Bank 1
Sensor 1) 15
P0152 A O2 Sensor Circuit High
Voltage (Bank 2
Sensor 1) 1. No DTC relating to ECT sensor, CMP sensor, CKP sensor,
VSS, injector control circuit, ignition control circuit and O2
sensor circuit no activity (bank 1 & 2).
2. Engine speed is between 1000rpm and 4000rpm.
3. Engine coolant temperature is between 70
and 110
.
4. Vehicle speed is between 0km/h and 120km/h.
5. Engine load is between 80% and 160%.
6. Throttle position fluctuation is below 0.28V.
7. O2 sensor bank 1 or bank 2 output voltage is below
600mV for 50 seconds. "Open Loop" fuel control.

CIRCUIT DESCRIPTION
The Engine Control Module (ECM) supplies a bias
voltage of about 450 mV between the heated oxygen
sensor (HO2S) signal high and signal low circuits. The
ECM constantly monitors the HO2S signal during
“closed loop" operation and compensates for a rich o
r
lean condition by decreasing or increasing injector pulse
width as necessary. If the HO2S voltage remains
excessively high for an extended period of time, DTC
P0132 or P0152 will be set.
DIAGNOSTIC AIDS
Check the following items:
 Fuel pressure – The system will go rich if pressure is
too high. The ECM can compensate for some
increase. However, if fuel pressure is too high, a DTC
P0132 or P0152 may be set. Refer to 6E-116 Fue
l
System Diagnosis.
 Perform “Injector Balance Test" – Refer to 6E-116
Fuel System Diagnosis.
 Check the canister for fuel saturation – If full of fuel,
check canister control and hoses.
 MAF sensor –The system can go rich if MAF senso
r
signal indicates an engine airflow measurement that
is not correct. Disconnect the MAF sensor to see it
the rich condition is corrected. If so, replace the MAF
sensor.

 Check for a leak in the fuel pressure regulato
r
diaphragm by checking the vacuum line to the
regulator for the presence of fuel. There should be no
fuel in the vacuum line.

An intermittent throttle position sensor output will
cause the system to go rich due to a false indication
of the engine accelerating.
 Shorted Heated Oxygen Sensor (HO2S) –If the
HO2S is internally shorted, the HO2S voltage
displayed on the Tech 2 will be over 1 volt. Try
disconnecting the affected HO2S with the key “ON,"
engine “OFF." If the displayed HO2S voltage
changes from over 1000 mV to around 450 mV,
replace the HO2S. Silicon contamination of the
HO2S can also cause a high HO2S voltage to be
indicated. This condition is indicated by a powdery
white deposit on the portion of the HO2S exposed to
the exhaust stream. If contamination is noticed,
replace the affected HO2S.
 Open HO2S Signal Circuit or Faulty HO2S–
A poor
connection or open in the HO2S signal circuit can
cause the DTC to set during deceleration fuel mode.
An HO2S which is faulty and not allowing a full
voltage swing between the rich and lean thresholds
can also cause this condition. Operate the vehicle by
monitoring the HO2S voltage with a Tech 2. If the
HO2S voltage is limited within a range between 300
mV to 600 mV, check the HO2S signal circuit wiring
and associated terminal conditions.
 If none of the above conditions are present, replace
the affected HO2S.

6E-208 3.5L ENGINE DRIVEABILITY AND EMISSIONS
CIRCUIT DESCRIPTION
 The Engine Control Module (ECM) supplies a bias
voltage of about 450 mV between the heated oxygen
sensor (HO2S) high and low circuits. The ECM
constantly monitors the HO2S signal during “closed
loop" operation and compensates for a rich or lean
condition by decreasing or increasing injector pulse
width as necessary. If the HO2S voltage remains a
t
or near the 450 mV bias for an extended period of
time, DTC P0134 or P0154 will be set, indicating an
open sensor signal or sensor low circuit.
DIAGNOSTIC AIDS
Check for the following conditions:
 Poor connection or damaged harness – Inspect the
harness connectors for backed-out terminals,
improper mating, broken locks, improperly formed o
r
damaged terminals, poor terminal-to-wire connection,
and damaged harness.
 Faulty HO2S heater or heater circuit –With the
ignition “ON," engine “OFF," after a cool down period,
the HO2S voltage displayed on the Tech 2 is
normally 455-460 mV. A reading over 1000 m
V
indicates a signal line shorted to voltage. A reading
under 5 mV indicates a signal line shorted to ground
or signal lines shorted together.
 Intermittent test –With the Ignition “ON," monitor the
HO2S signal voltage while moving the wiring harness
and related connectors. If the fault is induced, the
HO2S signal voltage will change. This may help
isolate the location of the malfunction.


Diagnostic Trouble Code (DTC) P0134 (Flash Code 15) O2 Sensor Circuit No
Activity Detected (Bank 1 Sensor 1)
Diagnostic Trouble Code (DTC) P0154 (Flash Code 15) O2 Sensor Circuit No
Activity Detected (Bank 2 Sensor 1)
Step Action Value (s) Yes No
1 Was the "On-Board Diagnostic (OBD) System Check"
performed?
- Go to Step 2 Go to On Board
Diagnostic (OBD)
System Check
2
1. Connect the Tech 2.
2. Review and record the failure information.
3. Select "F0: Read DTC Infor By Priority" in "F0:
Diagnostic Trouble Code".
Is the DTC P0134 or P0154 stored as "Present
Failure"?
- Go to Step 3 Refer to
Diagnostic Aids
and Go to Step 3
3
1. Using the Tech2, ignition "On" and engine "Off".
2. Select "Clear DTC Information" with the Tech2 and
clear the DTC information.
3. Operate the vehicle and monitor the "F5: Failed
This Ignition" in "F2: DTC Information"
Was the DTC P0134 or P0154 stored in this ignition
cycle?
- Go to Step 4 Refer to
Diagnostic Aids
and Go to Step 4

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-275
CIRCUIT DESCRIPTION
The canister purge solenoid valve is controlled by the
Engine Train Control Module (ECM).
At an appropriate time, the EVAP canister purge
solenoid is “ON," allowing engine vacuum to draw a
small vacuum on the entire evaporative emissions
system.
DIAGNOSTIC AIDS
An intermittent may be caused by the following:
 Poor connections.
 Mis routed harness.
 Rubbed through wire insulation.
 Broken wire inside the insulation.
Check for the following conditions:

 Poor connection at ECM-Inspect harness connectors
for backed out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal to wire connection.
 Damaged harness-Inspect the wiring harness fo
r
damage. If the harness appears to be OK, observe
the EVAP purge solenoid display on the Tech 2 while
moving connectors and wiring harnesses related to
the sensor.
A change in the display will indicate the location o
f
the fault. If DTC P0444 or P0445 cannot be
duplicated, the information included in the Failure
Records data can be useful in determined vehicle
mileage since the DTC was last set.
If it is determined that the DTC occurs intermittently,
performing the DTC P0444 or P0445 Diagnostic
Chart may isolate the cause of the fault.


Diagnostic Trouble Code (DTC) P0444 EVAP Purge Solenoid
Valve Circuit Low Voltage
Diagnostic Trouble Code (DTC) P0445 EVAP Purge Solenoid
Valve Circuit High Voltage

Step Action Value (s) Yes No
1
Was the "On-Board Diagnostic (OBD) System Check"
performed?
- Go to Step 2 Go to On Board
Diagnostic (OBD)
System Check
2
1. Connect the Tech 2.
2. Review and record the failure information.
3. Select "F0: Read DTC Infor By Priority" in "F0:
Diagnostic Trouble Code".
Is the DTC P0444 or P0445 stored as "Present
Failure"?
- Go to Step 3 Refer to
Diagnostic Aids
and Go to Step 3
3
1. Using the Tech2, ignition "On" and engine "Off".
2. Select "Clear DTC Information" with the Tech2 and
clear the DTC information.
3. Operate the vehicle and monitor the "F5: Failed
This Ignition" in "F2: DTC Information"
Was the DTC P0444 or P0445 stored in this ignition
cycle?
- Go to Step 4 Refer to
Diagnostic Aids
and Go to Step 4

6C-4 ENGINE FUEL (C24SE)

Fuel Metering
Engine Control Module (ECM) is in complete control of this fuel
delivery system during normal driving conditions.
The intake manifold function, like that of a diesel, is used only
to let air into the engine. The fuel is injected by separate
injectors that are mounted over the intake manifold.
The Manifold Absolute Pressure (MAP) sensor measures the
changes in the intake manifold pressure which result from
engine load and speed changes, which the MAP senso
r
converts to a voltage output.
This sensor generates the voltage to change corresponding to
the flow of the air drawn into the engine.
The changing voltage is transformed into an electric signal and
provided to the ECM.
With receipt of the signals sent from the MAP sensor, Intake
Air Temperature sensor and others, the ECM determines an
appropriate fuel injection pulse width feeding such information
to the fuel injector valves to effect an appropriate air/fuel ratio.
The Multiport Fuel Injection system utilizes an injection system
where the injectors turn on at every crankshaft revolution. The
ECM controls the injector on time so that the correct amount o
f
fuel is metered depending on driving conditions.
Two interchangeable "O" rings are used on the injector tha
t
must be replaced when the injectors are removed.
The fuel rail is attached to the top of the intake manifold and
supplies fuel to all the injectors.
Fuel is recirculated through the rail continually while the engine
is running. This removes air and vapors from the fuel as well
as keeping the fuel cool during hot weather operation.
The fuel pressure control valve that is mounted on the fuel rail
maintains a pressure differential across the injectors under all
operating conditions. It is accomplished by controlling the
amount of fuel that is recirculated back to the fuel tank based
on engine demand.
See Section "Driveability and Emission" for more information
and diagnosis.

6E–48 ENGINE DRIVEABILITY AND EMISSIONS
GENERAL DESCRIPTION FOR ECM AND
SENSORS
Engine Control Module (ECM)
The engine control module (ECM) is located on the
intake manifold. The ECM controls the following.
Fuel metering system
Ignition timing
On-board diagnostics for electrical functions.
The ECM constantly observes the information from vari-
ous sensors. The ECM controls the systems that affect
vehicle performance. And it performs the diagnostic
function of the system.
The function can recognize operational problems, and
warn to the driver through the check engine lamp, and
store diagnostic trouble code (DTC). DTCs identify the
problem areas to aid the technician in marking repairs.
The input / output devices in the ECM include analog to
digital converts, signal buffers, counters and drivers.
The ECM controls most components with electronic
switches which complete a ground circuit when turned
on.
Inputs (Operating condition read):
Battery voltage
Electrical ignition
Ex haust oxygen content
Intake manifold pressure
Intake air temperature
Engine coolant temperature
Crankshaft positionKnock signal
Throttle position
Vehicle speed
Power steering pressure
Air conditioning request on or off
Outputs (Systems controlled):
Ignition control
Fuel control
Idle air control
Fuel pump
EVAP canister purge
Air conditioning
Diagnostics functions
Manifold Absolute Pressure (MAP) Sensor
The MAP sensor is a strain gage. A pressure strains the
resistance on the silicon base. At that time the
resistance value changes. And it changes voltage. In
other words it measures a pressure value. It is installed
to the intake manifold. Output voltage of the MAP
sensor is low as pressure is low. (1) J1 Port
(2) J2 Port
12
C h arac teris tic of MA P S ens or -R ef erenc e-
0 0.51 1.52 2.53 3.54 4.55
15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105
Mani fold A bs olute P res s ure (K P a) (T ec h2 Reading)
Output Voltage (V)