2004 ISUZU TF SERIES injector

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-217
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)
P0172 B O2 Sensor System Too
Rich (Bank 1) 45
P0175 B O2 Sensor System Too
Rich (Bank 2) 1. No DTC relating to MAF sensor, IAT sensor, ECT sensor,
TPS, CMP sensor, CKP sensor, VSS, injector control
circuit, ignition control circuit, O2 sensor circuit low voltage
& high voltage (bank 1 & 2) and O2 sensor circuit no
activity (bank 1 & 2).
2. Engine speed is more than 600rpm.
3. Intake air temperature is more than 50
C.
4. Engine coolant temperature is between 35
C and 120
C.
5. Engine load is more than 20%.
6. EVAP purge solenoid valve on-duty is below 100%.
7. Air-fuel ratio correction volume is below 50% for 20
seconds. No fail-safe function.


CIRCUIT DESCRIPTION
To provide the best possible combination of driveability,
fuel economy, and emission control, a “closed loop"
air/fuel metering system is used. While in “closed loop,"
the Engine Control Module (ECM) monitors the heated
oxygen sensors (HO2S) signals and adjusts fuel
delivery based upon the HO2S signal voltages.
A
change made to fuel delivery will be indicated by the
long and short term fuel trim values which can be
monitored with a Tech 2. Ideal fuel trim values are
around 0%; if the HO2S signals are indicating a lean
condition the ECM will add fuel, resulting in fuel trim
values above 0%. If a rich condition is detected, the fuel
trim values will be below 0%, indicating that the ECM is
reducing the amount of fuel delivered. If an excessively
rich condition is detected on Bank 1, the ECM will se
t
DTC P0172 or P0175.
The ECM's maximum authority to control long term fuel
trim allows a range between –15% (automatic
transmission) or –12 (manual transmission) and +20%.
The ECM's maximum authority to control short term fuel
trim allows a range between –11% and +20%. The ECM
monitors fuel trim under various engine speed/load fuel
trim cells before determining the status of the fuel trim
diagnostic.

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 HO2S display on the Tech 2 while moving
connectors and wiring harnesses related to the
engine harness. A change in the display will indicate
the location of the fault.

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-219
Step Action Value (s) Yes No
6
1. Using the Tech 2, ignition "On" and engine "Off".
2. Monitor the "Throttle Position" in the data display.
Does the Tech 2 indicate correct "Throttle Position"
from 0% to 100% depending on accelerator pedal
operation?
- Go to Step 8 Go to Step 7
7
1. Using the Tech 2, ignition "On" and engine "Off".
2. Monitor the "Throttle Position" in the data display.
3. Adjust the TPS within 0% to 100%.
Is the action complete?
- Verify repair -
8
Check for the following conditions.

Objects blocking the throttle valve.

Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found?
- Verify repair Refer to DTC
P0121 and Go to
Step 9
9
1. Using the Tech 2, ignition "On" and engine "On".
2. Select the "Miscellaneous Test" and perform the
"IAC Control" in the "IAC System".
3. Operate the Tech 2 in accrodance with procedure.
Was the engine speed changed, when the IAC Valve
is operating step by step?
-
Go to Step 11
Go to Step 10
10
Check for the following conditions.

Objects blocking the IAC Valve.

Objects blocking the throttle valve.

Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found?
- Verify repair Refer to DTC
P1508/P1509
and Go to Step
11
11
Check for injector for the affected bank.
Refer to 6E-106 "Injector Coil Test & Injector Balance
Test Procedure".
Was the injector operation correct?
- Go to Step 12 Refer to Injector
Coil Test &
Injector Balance
Test Procedure
12
Check for fuel pressure.
Refer to 6E-116 "Fuel System Diagnosis".
Was the fuel pressure correct?
- Go to Step 13 Refer to Fuel
System
Diagnosis
13
Replace the O2 sensor for the affected bank.
Was the problem solved?
- Verify repair Go to Step 14
14
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 15

6E-222 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)
P1171 D Fuel Supply System
Lean During Power
Enrichment (Bank 1) 44

P1172 D Fuel Supply System
Lean During Power
Enrichment (Bank 2) 1. No DTC relating to MAF sensor, IAT sensor, ECT sensor,
TPS, CMP sensor, CKP sensor, VSS, injector control
circuit, ignition control circuit, O2 sensor circuit low voltage
& high voltage (bank 1 & 2) and O2 sensor circuit no
activity (bank 1 & 2).
2. Engine speed is between 1000rpm and 6000rpm.
3. Intake air temperature is below 70
C.
4. Engine coolant temperature is between 30
C and 120
C.
5. Engine load is between 150 and 255.
6. Throttle position output is more than 2.22V and fluctuation
is below 0.28V.
7. Except fuel cut operation.
8. O2 sensor output voltage below 250mV for 10 seconds. No fail-safe function.


CIRCUIT DESCRIPTION
The engine control module (ECM) internal circuitry can
identify if the vehicle fuel system is capable of supplying
adequate amounts of fuel during heavy acceleration
(power enrichment). The ECM monitors the voltage o
f
the oxygen sensor during power enrichment. When a
power enrichment mode of operation is requested
during “closed loop" operation (by heavy acceleration),
the ECM will provide more fuel to the engine. Unde
r
these conditions the ECM should detect a “rich"
condition (high oxygen sensor voltage). If this “rich"
exhaust is not detected at this time, a DTC P1171 o
r
P1172 will set. A plugged fuel filter, restricted fuel line,
restricted in-tank filter or defective fuel pump can
prevent adequate amouts of fuel from being supplied
during power enrichment mode.

DIAGNOSTIC AIDS
 A restricted fuel filter or fuel line, restricted in-tank
filter, or a defective fuel pomp may supply adequate
amounts of fuel at idle, but may not be able to supply
enough fuel during heavy acceleration.
 Water or alcohol in the fuel may cause low HO2S
voltage during acceleration.
 Check for faulty or plugged fuel injector(s).
 Check for low fuel.

6E-224 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No
6
1. Using the Tech 2, ignition "On" and engine "Off".
2. Monitor the "Throttle Position" in the data display.
Does the Tech 2 indicate correct "Throttle Position"
from 0% to 100% depending on accelerator pedal
operation?
- Go to Step 8 Go to Step 7
7
1. Using the Tech 2, ignition "On" and engine "Off".
2. Monitor the "Throttle Position" in the data display.
3. Adjust the TPS within 0% to 100%.
Is the action complete?
- Verify repair -
8
Check for the following conditions.

Objects blocking the throttle valve.

Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found?
- Verify repair Refer to DTC
P0121 and Go to
Step 9
9
1. Using the Tech 2, ignition "On" and engine "On".
2. Select the "Miscellaneous Test" and perform the
"IAC Control" in the "IAC System".
3. Operate the Tech 2 in accrodance with procedure.
Was the engine speed changed, when the IAC Valve
is operating step by step?
-
Go to Step 10
Go to Step 10
10
Check for the following conditions.

Objects blocking the IAC Valve.

Objects blocking the throttle valve.

Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found?
- Verify repair Refer to DTC
P1508/P1509
and Go to Step
11
11
Check for injector for the affected bank.
Refer to 6E-106 "Injector Coil Test & Injector Balance
Test Procedure".
Was the injector operation correct?
- Go to Step 12 Refer to Injector
Coil Test &
Injector Balance
Test Procedure
12
Check for fuel pressure.
Refer to 6E-116 "Fuel System Diagnosis".
Was the fuel pressure correct?
- Go to Step 13 Refer to Fuel
System
Diagnosis
13
Replace the O2 sensor for the affected bank.
Was the problem solved?
- Verify repair Go to Step 14
14
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 15

6E-226 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0201 (FLASH CODE 31) INJECTOR 1
CONTROL CIRCUIT
DIAGNOSTIC TROUBLE CODE (DTC) P0202 (FLASH CODE 31) INJECTOR 2
CONTROL CIRCUIT
DIAGNOSTIC TROUBLE CODE (DTC) P0203 (FLASH CODE 31) INJECTOR 3
CONTROL CIRCUIT
DIAGNOSTIC TROUBLE CODE (DTC) P0204 (FLASH CODE 31) INJECTOR 4
CONTROL CIRCUIT
DIAGNOSTIC TROUBLE CODE (DTC) P0205 (FLASH CODE 31) INJECTOR 5
CONTROL CIRCUIT
DIAGNOSTIC TROUBLE CODE (DTC) P0206 (FLASH CODE 31) INJECTOR 6
CONTROL CIRCUIT





RTW36EMF000901

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.

6E-228 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0201 (Flash Code 31) Injector 1
Control Circuit
Diagnostic Trouble Code (DTC) P0202 (Flash Code 31) Injector 2
Control Circuit
Diagnostic Trouble Code (DTC) P0203 (Flash Code 31) Injector 3
Control Circuit
Diagnostic Trouble Code (DTC) P0204 (Flash Code 31) Injector 4
Control Circuit
Diagnostic Trouble Code (DTC) P0205 (Flash Code 31) Injector 5
Control Circuit
Diagnostic Trouble Code (DTC) P0206 (Flash Code 31) Injector 6
Control Circuit

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 P0201, P0202, P0203, P0204, P0205 or
P0206 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 P0201, P0202, P0203, P0204, P0205 or
P0206 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-229
Step Action Value (s) Yes No
4
Check for poor/faulty connection at the injector or
ECM connector. If a poor/faulty connection is found,
repair as necessary.
Was the problem found?
E-61(B)



E-60(A)


E-6/E-7/E-8/E-9/
E-51/E-52


- Verify repair Go to Step 5
5
Visually check the injector for affected cylinder.
Was the problem found?
- Go to Step 11 Go to Step 6
6
Using the DVM and check the injector coil.
1. Ignition "Off", engine "Off".
2. Disconnect injector connector for the affected
cylinder.
3. Measure the resistance of injector coil.
Does the tester indicate standard resistance?








 
Injector


Approximately
15 at 20C
Go to Step 7
Go to Step 11