2004 ISUZU TF SERIES ESP

6E-82 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Tech 2
Parameter
Units Idle 2000rpm Definitions
19 B1 Short Term
Fuel Trim (Bank
1)
% -10
20 -10
20
20 B2 Short Term
Fuel Trim (Bank
2)
% -10
20 -10
20
The short term fuel trim to a bank represents a short term correction to the bank fuel
delivery by the ECM in response to the amount of time the bank fuel control oxygen
sensor voltage spends above or below the 450mV threshold.
If the oxygen sensor voltage has mainly remained less than 450mV, indicating a lean
air/fuel, short term fuel trim will increase into the positive range above 0% and the
ECM will pass fuel.
If the oxygen sensor voltage stays mainly above the threshold, short term fuel trim
will decrease below 0% into the negative range while the ECM reduces fuel delivery
to compensate for the indicated rich condition.
Under certain conditions such as extended idle and high ambient temperatures,
canister purge may cause short term fuel trim to read in the negative range during
normal operation.
Excessive short term fuel trim values may indicate an rich or lean condition.
21 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.
22 Fuel Trim
Learned (Bank 1) Yes/No Yes Yes
23 Fuel Trim
Learned (Bank 2) Yes/No Yes Yes
When conditions are appropriate for enabling long term fuel trim corrections, fuel trim
learn will display "Yes".
This indicates that the long term fuel trim is responding to the short term fuel trim.
If the fuel trim lean displays "No", then long term fuel trim will not respond to changes
in short term fuel trim.
24 B1S1 Status
(Bank 1 Sensor 1)
Rich / Lean Rich / Lean Rich / Lean
25 B2S1 Status
(Bank 2 Sensor 1)
Rich / Lean Rich / Lean Rich / Lean
This displays dependent on the exhaust oxygen sensor output voltage.
Should fluctuate constantly "Rich" and "Lean" in closed loop.

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.

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E -89

After recording the snapshot in Tech2, transfer the data
from Tech2 to PC by the below procedures.
1.
Start TIS2000.
2.
Select [Snapshot Upload] on the TIS2000 start
screen.
3.
Select [Upload from trouble diagnosis tool (transfe
r
from diagnosis tester)] or click the corresponding
icon of the tool bar.
4.
Select Tech2, and transfer the recorded snapshot
information.
5.
Select the transferred snapshot.
6.
After ending transfer of the snapshot, data
parameter list is displayed on the screen. 3. Snapshot data is displayed with TIS2000
[Snapshot Upload] function.
Snapshot is stored in the PC hard disk or floppy disk,
and can be displayed any time.
Stored snapshot can be displayed by the below
procedures.
1.
Start TIS2000.
2.
Select [Snapshot Upload] on the TIS2000 start
screen.
3.
Select [Open the existing files] or click the
corresponding icon of the tool bar.
4.
Select the transferred snapshot.
5.
Open the snapshot, to display the data paramete
r
list on the screen.



Graph display Values and graphs (Max. 3 graphs):




1.
Click the icon for graph display. [Graph Parameter]
window opens.
2.
Click the first graph icon of the window upper part,
and select one parameter from the list of the
window lower part. Selected parameter is
displayed nest to the graph icon. Graph division
can be selected in the field on the parameter right
side.
3.
Repeat the same procedures with the 2nd and 3rd
icons.
4.
After selecting all parameters to be displayed
(Max. 3 parameters), click [OK] button.
5.
Parameter selected is displayed in graph form on
the right of the data parameter on the screen.

6.
Graph display can be moved with the navigation
icon.
7.
For displaying another parameter by graph, click
the parameter of the list, drug the mouse to the
display screen while pressing the mouse button
and release the mouse button. New parameter is
displayed at the position of the previous
parameter. For displaying the graph display screen
in full size, move the cursor upward on the screen.
When the cursor is changed to the magnifying
glass form, click the screen. Graph screen is
displayed on the whole screen.

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****

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-259
CIRCUIT DESCRIPTION
The engine control module (ECM) monitors the EGR
valve pintle position input to ensure that the valve
responds properly to commands from the PCM, and to
detect a fault if pintle position is differen
t
fromcommanded position.
DIAGNOSTIC AIDS
Check for the following conditions:

Excessive carbon deposit on EGR valve shaf
t
maycause EGR stuck open or unsmooth operation.
Those carbon deposit may occur by unusual
portoperation. Clean up carbon may make
smoothfunction of EGR valve.


Poor connection or damaged harness Inspec
t
thewiring harness for damage. If the harness
appears to be OK, observe the EGR actual position
display on the Tech 2 while moving connectors and
wiring harnesses related to EGR valve. A change in
the display will indicate the location of the fault.

Diagnostic Trouble Code (DTC) P0404 (Flash Code 32) EGR Circuit
Range/Perfomance (Open Valve)
Diagnostic Trouble Code (DTC) P1404 (Flash Code 32) EGR Circuit
Range/Perfomance (Closed Valve)

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 P0404 or P1404 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 P0404 or P1404 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-263
DIAGNOSTIC TROUBLE CODE (DTC) P0405 (FLASH CODE 32)
EGR CIRCUIT LOW



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)
32 P0405 B EGR Circuit Low 1. No DTC relating to EGR circuit range/performance.
2. EGR solenoid valve on-duty ratio is more than 40%.
3. EGR position sensor output voltage is below 0.3V. No fail-safe function.

CIRCUIT DESCRIPTION
The engine control module (ECM) monitors the EGR
valve pintle position input to ensure that the valve
responds properly to command from the ECM. If curren
t
pintle position voltage indicates less than 0.3 V the ECM
will set DTC P0405.

DIAGNOSTIC AIDS
Check for the following conditions:
 Poor connection or damaged harness –Inspect the
wiring harness for damage. If the harness appears to
be OK, observe the EGR actual position display on
the Tech 2 while moving connectors and wiring
harnesses related to EGR valve. A change in the
display will indicate the location of the fault.

6E-268 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0406 (FLASH CODE 32)
EGR CIRCUIT HIGH



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)
32 P0406 B EGR Circuit High 1. No DTC relating to EGR circuit range/performance.
2. EGR solenoid valve on-duty ratio is below 40%.
3. EGR position sensor output voltage is more than 4.6V. No fail-safe function.


CIRCUIT DESCRIPTION
The engine control module (ECM) monitors the EGR
valve pintle position input to ensure that the valve
responds properly to command from the ECM. If curren
t
pintle position voltage indicates more than 4.6 V the
ECM will set DTC P0406.

DIAGNOSTIC AIDS
Check for the following conditions:
 Poor connection or damaged harness –Inspect the
wiring harness for damage. If the harness appears to
be OK, observe the EGR actual position display on
the Tech 2 while moving connectors and wiring
harnesses related to EGR valve. A change in the
display will indicate the location of the fault.

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.