key ISUZU TF SERIES 2004 Manual PDF

Page 2053 of 4264

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-57
Starting Mode
When the ignition is first turned "ON," the ECM
energizes the fuel pump relay for two seconds to allo
w
the fuel pump to build up pressure. The ECM then
checks the engine coolant temperature (ECT) senso
r
and the throttle position sensor to determine the proper
air/fuel ratio for starting.
The ECM controls the amount of fuel delivered in the
starting mode by adjusting how long the fuel injectors
are energized by pulsing the injectors for very short
times.

Fuel Metering System Components
The fuel metering system is made up of the following
parts.
 Fuel injector
 Throttle Body
 Fuel Rail
 Fuel Pressure regulator
 ECM
 Crankshaft position (CKP) sensor
 Camshaft position (CMP) sensor
 Idle air control valve
 Fuel pump

Fuel Injector
The sequential multi-port fuel injection fuel injector is a
solenoid operated device controlled by the ECM. The
ECM energizes the solenoid, which opens a valve to
allow fuel delivery.
The fuel is injected under pressure in a conical spray
pattern at the opening of the intake valve. Excess fuel
not used by the injectors passes through the fuel
pressure regulator before being returned to the fuel
tank.

Fuel Pressure Regulator
The fuel pressure regulator is a diaphragm-operated
relief valve mounted on the fuel rail with fuel pump
pressure on one side and manifold pressure on the
other side. The fuel pressure regulator maintains the
fuel pressure available to the injector at three times
barometric pressure adjusted for engine load. It may be
serviced separate.
If the pressure is too low, poor performance and a DTC
P0131, P0151, P0171, P0174, P1171 or P1174 will be
the result. If the pressure is too high, excessive odo
r
and/or a DTC P0132, P0152, P0172 or P0175 will be
the result. Refer to Fuel System Diagnosisfo
r
information on diagnosing fuel pressure conditions.
Fuel Rail
The fuel rail is mounted to the top of the engine and
distributes fuel to the individual injectors. Fuel is
delivered to the fuel inlet tube of the fuel rail by the fuel
lines. The fuel goes through the fuel rail to the fuel
pressure regulator. The fuel pressure regulato
r
maintains a constant fuel pressure at the injectors.
Remaining fuel is then returned to the fuel tank.







055RV009
Fuel Pump Electrical Circuit
When the key is first turned "ON," the ECM energizes
the fuel pump relay for two seconds to build up the fuel
pressure quickly. If the engine is not started within two
seconds, the ECM shuts the fuel pump off and waits
until the engine is cranked. When the engine is cranked
and the 58 X crankshaft position signal has been
detected by the ECM, the ECM supplies 12 volts to the
fuel pump relay to energize the electric in-tank fuel
pump.
An inoperative fuel pump will cause a "no-start"
condition. A fuel pump which does not provide enough
pressure will result in poor performance.

Camshaft Position (CMP) Sensor Signal
The ECM uses this signal to determine the position o
f
the number 1 piston during its power stroke, allowing
the ECM to calculate true sequential multiport fuel
injection. Loss of this signal will set a DTC P0341. If the
CMP signal is lost while the engine is running, the fuel
injection system will shift to a calculated sequential fuel
injection based on the last fuel injection pulse, and the
engine will continue to run. The engine can be restarted
and will run in the calculated sequential mode as long
as the fault is present, with a 1-in-6 chance of being
correct.

Page 2066 of 4264

6E-70 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Fuel Quality
Fuel quality is not a new issue for the automotive
industry, but its potential for turning on the MIL (“Check
Engine" lamp) with OBD systems is new.
Fuel additives such as “dry gas" and “octane
enhancers" may affect the performance of the fuel. The
Reed Vapor Pressure of the fuel can also create
problems in the fuel system, especially during the spring
and fall months when severe ambient temperature
swings occur. A high Reed Vapor Pressure could sho
w
up as a Fuel Trim DTC due to excessive canister
loading. High vapor pressures generated in the fuel
tank can also affect the Evaporative Emission
diagnostic as well.
Using fuel with the wrong octane rating for your vehicle
may cause driveability problems. Many of the majo
r
fuel companies advertise that using “premium" gasoline
will improve the performance of your vehicle. Mos
t
premium fuels use alcohol to increase the octane rating
of the fuel. Although alcohol-enhanced fuels may raise
the octane rating, the fuel's ability to turn into vapor in
cold temperatures deteriorates. This may affect the
starting ability and cold driveability of the engine.
Low fuel levels can lead to fuel starvation, lean engine
operation, and eventually engine misfire.
Non-OEM Parts
All of the OBD diagnostics have been calibrated to run
with OEM parts.
Aftermarket electronics, such as cellular phones,
stereos, and anti-theft devices, may radiate EMI into the
control system if they are improperly installed. This may
cause a false sensor reading and turn on the MIL
(“Check Engine" lamp).
Environment
Temporary environmental conditions, such as localized
flooding, will have an effect on the vehicle ignition
system. If the ignition system is rain-soaked, it can
temporarily cause engine misfire and turn on the MIL
(“Check Engine" lamp).
Vehicle Marshaling
The transportation of new vehicles from the assembly
plant to the dealership can involve as many as 60 key
cycles within 5Km miles of driving. This type o
f
operation contributes to the fuel fouling of the spark
plugs and will turn on the MIL (“Check Engine" lamp).

Poor Vehicle Maintenance
The sensitivity of OBD diagnostics will cause the MIL
(“Check Engine" lamp) to turn on if the vehicle is no
t
maintained properly. Restricted air filters, fuel filters,
and crankcase deposits due to lack of oil changes o
r
improper oil viscosity can trigger actual vehicle faults
that were not previously monitored prior to OBD. Poo
r
vehicle maintenance can not be classified as a
“non-vehicle fault", but with the sensitivity of OBD
diagnostics, vehicle maintenance schedules must be
more closely followed.
Severe Vibration
The Misfire diagnostic measures small changes in the
rotational speed of the crankshaft. Severe driveline
vibrations in the vehicle, such as caused by an
excessive amount of mud on the wheels, can have the
same effect on crankshaft speed as misfire.
Related System Faults
Many of the OBD system diagnostics will not run if the
ECM detects a fault on a related system or component.
One example would be that if the ECM detected a
Misfire fault, the diagnostics on the catalytic converte
r
would be suspended until Misfire fault was repaired. If
the Misfire fault was severe enough, the catalytic
converter could be damaged due to overheating and
would never set a Catalyst DTC until the Misfire faul
t
was repaired and the Catalyst diagnostic was allowed to
run to completion. If this happens, the customer may
have to make two trips to the dealership in order to
repair the vehicle.
Maintenance Schedule
Refer to the Maintenance Schedule.
Visual/Physical Engine Compartment
Inspection
Perform a careful visual and physical engine
compartment inspection when performing any
diagnostic procedure or diagnosing the cause of an
emission test failure. This can often lead to repairing a
problem without further steps. Use the following
guidelines when performing a visual/physical inspection:
 Inspect all vacuum hoses for punches, cuts,
disconnects, and correct routing.
 Inspect hoses that are difficult to see behind othe
r
components.
 Inspect all wires in the engine compartment fo
r
proper connections, burned or chafed spots, pinched
wires, contact with sharp edges or contact with ho
t
exhaust manifolds or pipes.

Page 2068 of 4264

6E-72 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Passive and Active Diagnostic Tests
A passive test is a diagnostic test which simply monitors
a vehicle system or component. Conversely, an active
test, actually takes some sort of action when performing
diagnostic functions, often in response to a failed
passive test.
Intrusive Diagnostic Tests
This is any on-board test run by the Diagnostic
Management System which may have an effect on
vehicle performance or emission levels.
Warm-Up Cycle
A warm-up cycle means that engine at temperature
must reach a minimum of 70
C (160F) andrise at
least 22
C (40F) over the course of a trip.
The Diagnostic Executive
The Diagnostic Executive is a unique segment of
software which is designed to coordinate and prioritize
the diagnostic procedures as well as define the protocol
for recording and displaying their results. The main
responsibilities of the Diagnostic Executive are listed as
follows:
 Commanding the MIL (“Check Engine" lamp) on and
off
 DTC logging and clearing
 Freeze Frame data for the first emission related DTC
recorded
 Current status information on each diagnostic
The Diagnostic Executive records DTCs and turns on
the MIL when emission-related faults occur. It can also
turn off the MIL if the conditions cease which caused
the DTC to set.
Diagnostic Information
The diagnostic charts and functional checks are
designed to locate a faulty circuit or component through
a process of logical decisions. The charts are prepared
with the requirement that the vehicle functioned
correctly at the time of assembly and that there are no
t
multiple faults present.
There is a continuous self-diagnosis on certain control
functions. This diagnostic capability is complemented
by the diagnostic procedures contained in this manual.
The language of communicating the source of the
malfunction is a system of diagnostic trouble codes.
When a malfunction is detected by the control module,
a diagnostic trouble code is set and the MIL (“Check
Engine" lamp) is illuminated.

Check Engine Lamp (MIL)
The Check Engine Lamp (MIL) looks the same as the
MIL you are already familiar with (“Check Engine"
lamp).
Basically, the MIL is turned on when the ECM detects a
DTC that will impact the vehicle emissions.
The MIL is under the control of the Diagnostic
Executive. The MIL will be turned on if an
emissions-related diagnostic test indicates a
malfunction has occurred. It will stay on until the
system or component passes the same test, for three
consecutive trips, with no emissionsrelated faults.
Extinguishing the MIL
When the MIL is on, the Diagnostic Executive will turn
off the MIL after three consecutive trips that a “tes
t
passed" has been reported for the diagnostic test tha
t
originally caused the MIL to illuminate.
Although the MIL has been turned off, the DTC will
remain in the ECM memory (both Freeze Frame and
Failure Records) until forty(40) warm-up cycles after no
faults have been completed.
If the MIL was set by either a fuel trim or misfire-related
DTC, additional requirements must be met. In addition
to the requirements stated in the previous paragraph,
these requirements are as follows:
 The diagnostic tests that are passed must occur with
375 RPM of the RPM data stored at the time the las
t
test failed.
 Plus or minus ten (10) percent of the engine load tha
t
was stored at the time the last failed.
 Similar engine temperature conditions (warmed up o
r
warming up ) as those stored at the time the last tes
t
failed.
Meeting these requirements ensures that the fault which
turned on the MIL has been corrected.
The MIL (“Check Engine" lamp) is on the instrumen
t
panel and has the following functions:
 It informs the driver that a fault that affects vehicle
emission levels has occurred and that the vehicle
should be taken for service as soon as possible.

As a bulb and system check, the MIL will come “ON"
with the key “ON" and the engine not running. When
the engine is started, the MIL will turn “OFF."
 When the MIL remains “ON" while the engine is
running, or when a malfunction is suspected due to a
driveability or emissions problem, a Powertrain
On-Board Diagnostic (OBD) System Check must be
performed. The procedures for these checks are
given in On-Board Diagnostic (OBD) System Check.
These checks will expose faults which may not be
detected if other diagnostics are performed first.

Page 2070 of 4264

6E-74 3.5L ENGINE DRIVEABILITY AND EMISSIONS

0.4 Sec 0.4 Sec
.

ON

OFF


3.2 Sec. 1.2 Sec. 3.2 Sec.


0.4 Sec 0.4 Sec
.
ON

OFF


3.2 Sec. 1.2 Sec.  3.2 Sec.



Self-diagnosis Start

Normal Code (12)
Trouble Code (32)


121212141414323232

In case DTC 14 & 32 are stored

Clearing Diagnostic Trouble Codes
Important: Do not clear DTCs unless directed to do so
by the service information provided for each diagnostic
procedure. When DTCs are cleared, the Freeze Frame
and Failure Record data which may help diagnose an
intermittent fault will also be erased from memory.
If the fault that caused the DTC to be stored into
memory has been corrected, the Diagnostic Executive
will begin to count the “warm-up" cycles with no furthe
r
faults detected, the DTC will automatically be cleared
from the ECM memory.
To clear Diagnostic Trouble Codes (DTCs), use the
Tech 2 “clear DTCs" or “clear information" function.
When clearing DTCs follow instructions supplied by the
Tech 2 manufacturer.
When a Tech 2 is not available, DTCs can also be
cleared by disconnecting one of the following sources
for at least thirty (30) seconds.
To prevent system damage, the ignition key must be
“OFF" when disconnecting or reconnecting battery
power.
 The power source to the control module. Examples:
fuse, pigtail at battery ECM connectors etc.
 The negative battery cable. (Disconnecting the
negative battery cable will result in the loss of othe
r
on-board memory data, such as preset radio tuning).
On-Board Diagnosis (Self-Diagnosis)
1. The Engine Control Module (ECM) conducts a
self-test of most of the wiring and components in
the system each time the key is turned to ON, and
can detect faults in the system while the key is ON.
If a fault is detected, the ECM will store a trouble
code in memory and flash the CHECK ENGINE
indicator to alert the driver.
2. The Diagnostic Trouble Codes (DTC) can be
displayed by shorting together terminals and the
Data Link Connector (DLC) located belo
w
Instrument Panel of drivers side.
The CHECK ENGINE indicator will flash DTC 12
three times, followed by any DTC.If several DTC are
stored, each DTC will be displayed three times. The
DTC will be displayed in numerical order. The DTC
display will continue as long as the DLC is shorted.
Some DTC can cause other DTC to be stored, It is
important to diagnose and repair the lowes
t
numbered DTC first before going on to the highe
r
numbered DTC.

Page 2071 of 4264

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-75
TECH 2 CONNECTION



Tech 2 scan tool is used to electrically diagnose the
automatic transmission system and to check the
system. The Tech 2 enhances the diagnosis efficiency
though all the troubleshooting can be done without the
Te c h 2 .
1. Configuration of Tech 2
 Tech 2 scan tool kit (No. 7000086), Tech 2
scan tool (No. 7000057) and DLC cable (No.
3000095).
 SAE 16/19 adapter (No. 3000098) (3), RS232
loop back connector (No. 3000112) (2) and
PCMCIA card (No. 3000117) (1).
2. Tech 2 Connection
 Check the key switch is turn OFF.
 Insert the PCMCIA card (1) into the Tech 2 (5).
 Connect the SAE 16/19 adapter (3) to the DLC




 Turn the key switch of the vehicle ON and press
the “PWR” key of the Tech 2.
 Check the display of the Tech 2.
NOTE: Be sure to check that the power is not
supplied to the Tech 2 when attaching or removing
the PCMCIA card.
Diagnosis with TECH 2
If No Codes are Set
 Refer to F1: Data Display and identify the electrical
faults that are not indicated by trouble code.
 Refer to "SYMPTOM DIAGNOSIS".

If Codes are Set
1. Record all trouble codes displayed by Tech 2 and
check id the codes are intermittent.
2. Clear the codes.
3. Drive the vehicle for a test to reproduce the faulty
status.
4. Check trouble codes again using the Tech 2.
5. If no codes is displayed by test driving, the fault is
intermittent. In this case, refer to "DIAGNOSIS
AIDS".
6. If a code is present, refer to DTC Chartfo
r
diagnosis.
7. Check trouble codes again using the Tech 2.


Page 2076 of 4264


6E-80 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Tech 2
Parameter
Units Idle 2000rpm Definitions
23 A/C Request (Air
Conditioning) On/Off Off Off This displays the air conditioner request signal. This should display "On" when the air
conditioner switch is switched on.
24 A/C Clutch On/Off Off Off This displays whether the ECM has commanded the A/C compressor clutch "On" or
"Off".
25 EVAP Purge
Solenoid
(Evaporative
Emission) % 50  80 0 This displays the duty signal from the ECM to control the canister purge solenoid
valve.
26 Fuel Trim Cell 49  52 13  17 This displays dependent on engine speed and MAF sensor reading.
A plot of engine speed versus MAF amount is divided into the cells.
Fuel trim cell indicates which cell is currently active.
27 Fuel Pump On/Off On On This displays operating status for the fuel pump main relay.
This should display "On" when the key switch is turned on and while engine is
running.
28 Deceleration Fuel
Cutoff Active/ Inactive Inactive Inactive The ECM will command the deceleration fuel mode when it detects a closed throttle
position while the vehicle is traveling.
While in decreasing fuel mode, the ECM will decrease the amount of fuel delivered
by entering open loop and decreasing the injector pulse width.
29 Power Enrichment Yes/No No No The ECM will command power enrichment mode "Yes" when a large increase in
throttle position and load is detected.
While in power enrichment mode, the ECM will increase the amount of fuel delivered
by entering open loop and increasing the injector pulse width.
30 Vehicle Speed km/h or mph 0 0 This displays vehicle speed.
The vehicle speed is measured by ECM from the vehicle speed sensor.
31 Cam Signal Present/ Missing Present Present This displays input signal from the camshaft position sensor.
When the correct pulse is generated, signal is received.
32 PSP Switch
(Power Steering
Pressure) Normal Pressure /
High Pressure Normal PressureNormal PressureThis displays the power steering pressure signal.
This should display "High Pressure" when the steering is steered.
33 Security Code
Status Programmable/
Not
Programmable Programmable Programmable This should display "Programmable" when the correct security code & secret code
are programmed.
34 Security Code Okay/ Not Okay Okay Okay This should display "Okay" when the security code is correctly accepted.
35 Immobilizer
System Normal /
Abnormal Normal Normal This should display "Normal" when the immobilizer is correctly operated.
36 Malfunction
Indicator Lamp On/Off Off Off This displays operating status for the Check Engine Lamp.
This should display "On" when the Check Engine Lamp is turned on.
37 Time From Start   This displays the engine time elapsed since the engine was started.
If the engine is stopped, engine run time will be reset to 00:00:00

Page 2079 of 4264

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E -83

MISCELLANEOUS TEST
The state of each circuit can be tested by using
miscellaneous test menus. Especially when DTC cannot
be detected, a faulty circuit can be diagnosed by testing
each circuit by means of these menus.
Even DTC has been detected, the circuit tests using
these menus could help discriminate between a
mechanical trouble and an electrical trouble.
Connect Tech 2 and select "Powertrain", "3.5L V6 6VE1
Hitachi" & "Miscellaneous Test".

F0: Lamps
F0: Malfunction Indicator Lamp
When the Tech 2 is operated, "Malfunction Indicato
r
Lamp (Check Engine Lamp)" is turned on or off.
The circuit is normal if the "Malfunction Indicator Lamp
(Check Engine Lamp)" in the instrument panel is turned
on or off in accordance with this operation.

F1: Relays
F0: Fuel Pump Relay
When the Tech 2 is operated, fuel pump relay signal
turns ON or OFF.
The circuit is normal if fuel pump sound is generated in
accordance with this operation when key switch is
turned ON.

"F1: A/C Clutch Relay"
When the Tech 2 is operated, A/C clutch relay signal
turns ON or OFF.
The circuit is normal if A/C compressor clutch is
energized in accordance with this operation when the
engine is running.

F2: EVAP
F0: Purge Solenoid
When the Tech 2 is operated, duty ratio of EVAP purge
solenoid is changed 10%-by-10%.

Purge Solenoid
Engine Speed 800 RPM
Desired Idle Speed 762 RPM
Engine Coolant Temperature 80 
C
Start Up ECT 50 
C
Intake Air Temperature 30 
C
Throttle Position 0 %
EVAP Purge Solenoid 10 %


Press "Increase" key.

Then, EVAP Purge Solenoid increases

10%-by-10%.

Press "Quit" Key.

F3: IAC System
F0: RPM Control
When the Tech 2 is operated, "Desired Idle Speed"
increases 50rpm-by-50rpm up to 1550rpm.
The circuit is normal if engine speed is changed in
accordance with this operation.
RPM Control
Engine Speed 850 RPM
Desired Idle Speed 850 RPM
Engine Coolant Temperature 80 
C
Start Up ECT 50 
C
Intake Air Temperature 30 
C
Throttle Position 0 %
Desired Idle Speed 850 RPM


Press "Increase" key.

Then, Desired Idle speed increases

50rpm-by-50rpm up to 1550rpm. Engine speed is
also changed by this operation.

Press "Quit" Key.

F0: IAC Control
When the Tech 2 is operated, "Idle Air Control"
increases or decreases 10steps-by-10steps up to
160steps.
The circuit is normal if idle engine speed is changed in
accordance with this operation.
IAC Control
Engine Speed 875 RPM
Desired Idle Speed 762 RPM
Engine Coolant Temperature 80 
Start Up ECT 50 
Intake Air Temperature 30 
Throttle Position 0 %
Idle Air Control 30 Steps


Press "Increase" key.

Then, Idle Air Control increases 10steps-by-
10steps up to 160steps.

Engine speed is also changed by this operation.

Press "Quit" Key.

Page 2080 of 4264

6E-84 3.5L ENGINE DRIVEABILITY AND EMISSIONS

F4: Fuel System
F0: Fuel Trim Reset
When the Tech 2 is operated, "Long Term Fuel Trim" is
reset to 0%.
Fuel Trim Reset
B1 Long Term Fuel Trim (Bank 1) 3 %
B2 Long Term Fuel Trim (Bank 2) 3 %
B1 Short Term Fuel Trim (Bank 1) 
1 %
B2 Short Term Fuel Trim (Bank 2) 
2 %
Fuel Trim Cell 53
Fuel Trim Learned (Bank 1) Yes
Fuel Trim Learned (Bank 2) Yes
B1 Long Term Fuel Trim 0%


Press "Reset" key.

Then, B1 & B2 Long Term Fuel Trim is reseted to
0%.

Press "Quit" Key.

Page 2087 of 4264

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E -91
SERVICE PROGRAMMING SYSTEM (SPS)
The procedure to program the control unit by using the
Service Programming System (SPS) software
contained in TIS2000 is explained below.
NOTE: 
 

If the Engine Control Module (ECM) was
programmed, the Immobilizer System must be
linked to the ECM: Refer to section 11
"Immobilizer System-ECM replacement" for the
ECM/Immobilizer linking procedure.

 

Should Tech2 display "SPS Procedure was not
successful", engine will not start, but no DTCs
are present, low battery voltage or poo
r
electrical connections should be the primary
suspects. Perform the SPS procedure again
after rectifying the fault/s.


IMPORTANT:
Perform the following checks before attempting to
program the control unit:

 

The Tech2 PCMCIA card is programmed with
the latest software release.

 

The latest release of TIS2000 is loaded on the
PC.

 

The vehicle battery is fully charged.

 

The control unit to be programmed is
connected to the vehicle.
1. Preparations of TIS 2000
1.
Connect Tech 2 to P/C.
2.
Check to see if Hardware Key is plugged into Port.
3.
Activate TIS 2000 by P/C.
4.
On the activating screen of TIS2000, choose
"Service Programming System"




5.
On the screen of "Diagnostic Tester and
Processing Program Selection", choose the one
that will comply with the following.

Diagnostic Tech 2 in use

New programming by the existing module or new
programming by the replaced/new module.

Fixing position of the control unit.
6.
Upon completion of the selection, push the button
of "Next".

Page 2137 of 4264

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-141
Flash
Code Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Related Failure Parts Related
ECM Pin
No. Related
Multiple
DTC
P1626 - Immobilizer No Signal No response from immobilizer control unit.
1. ECM and immobilizer control unit
communication circuit open circuit, short to
ground circuit or short to voltage circuit.
2. Electrical interference.
3. Magnetic interference.
4. ECM malfunction.
5. Immobilizer control unit malfunction.
6. Transponder key malfunction. B18/
B32 B**** P1631 - Immobilizer Wrong Signal Received response is not correct.
1. ECM malfunction.
2. Immobilizer control unit malfunction.
3. Transponder key malfunction. - B**** P1648 - Wrong Security Code Entered Received incorrect security code.
1. ECM malfunction.
2. Immobilizer control unit malfunction.
3. Transponder key malfunction. - B****
67
P1649 - Immobilizer Function Not
Programmed Immobilizer function is not programmed in the
ECM. 1. Engine does not start.
2. Check engine lamp flash.
No recovery
ECM malfunction. - B****

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