ISUZU AXIOM 2002 Service Repair Manual

6E±334
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0448 EVAP Vent Solenoid Circuit Short

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Install the Tech 2.
2. Ignition is ªONº,
3. Observe the EVAP vent solenoid reading on the
Tech 2.
Is the EVAP vent solenoid reading near the specified
value?
0%
Refer to
Diagnostic
Aids
Go to Step 3
3Check the signal circuit for canister vent solenoid valve.
1. Ignition is ªOFFº.
2. Disconnect the canister vent solenoid valve.
3. Disconnect the PCM.
4. Check the circuit between EVAP vent solenoid
connector and PCM connector.
Is the problem found?
ÐGo to Step 4Go to Step 5
4Repair the circuit as necessary.
Is the action complete?
ÐVerify repairÐ
5Check the canister vent solenoid valve. Using a DVM,
measure resistance for purge solenoid valve connector
terminal.
Is the vent solenoid valve resistance within the
specified values?
21.8-28.5

(at
68
F{20
C})
Go to Step 7Go to Step 6
6Replace the canister vent solenoid valve.
Is the action complete?
ÐVerify repairÐ
7Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed.
Refer to
ON-Vehicle Service in Power Control Module
and Sensors for procedures. And also refer to latest
Service Bulletin.
Check to see if the latest software is released or not.
And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.
Is the action complete?
ÐVerify repairÐ

6E±335
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0452 Fuel Tank Pressure Sensor (Vapor Pressure Sensor) Low Voltage
060R200050
Circuit Description
The powertrain control module (PCM) monitors fuel tank
pressure sensor (Vapor pressure sensor) of the
Enhanced Evap system. When the tank pressure output
indicates low voltage, PCM will set DTC P0452.
Conditions for Setting the DTC

Tank sensor output is less than 0.2 volts for 12.5 sec.

100 test failures within a 200 tests.
Action Taken When the DTC Sets

The PCM will ON the MIL after second trip with
detected the fault.

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in Failure
Records data.
Conditions for Clearing the MIL/DTC

The PCM will turn the MIL ªOFFº on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.
A history DTC P0402 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0404 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check for the following conditions:

Open circuit of 5 volt reference line ± Inspect wiring
harness from PCM to the sensor. The PCM turns
P0452, and P0107 at the same time.

Open circuit or short circuit to ground line ± Inspect
wiring harness from PCM to the sensor. The PCM turns
P0452 and P0107 at the same time.

Tank fuel pressure sensor malfunction may cause
P0452.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.

6E±336
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0452 ± Tank Pressure Sensor Low Voltage

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªONº, engine ªOFFº, review and record
Tech 2 Failure Records Data.
2. Operate the vehicle within Failure Records
conditions as noted.
3. Using a Tech 2, monitor ªDTCº info for DTC P0452
until the DTC P0452 test runs. Note the result.
Does the Tech 2 indicates DTC P0452 or P0452/P0107
failed this ignition?
Ð
P0452/P0107
turn on
Go to
Step 3
P0452 turns on
Go to
Step 6
Refer to
Diagnostic
Aids
31. Ignition ªOFFº.
2. Disconnect connector at the PCM.
3. Ignition ªONº.
4. At the PCM connector, measure voltage with a DVM
at F54 and S37 terminals.
Was the voltage in range?
4±6 VGo to Step 4Go to Step 10
41. Ignition ªOFFº.
2. Connect the PCM connector to the PCM.
3. Backprobe with a DVM at fuel tank pressure sensor
between 5 V reference terminal and sensor ground
terminal.
Was the voltage within range?
4±6 V
For P0452 go
to
Step 5 and
for P0107, go
to diagnosis
section.
Go to Step 5
51. Locate open wiring of 5 volt reference circuit from
the PCM to fuel tank pressure sensor.
2. Repair wiring harness.
Is the action complete?
ÐVerify repairÐ
61. Ignition ªONº
2. At the PCM connector, backprobe with a DVM at the
sensor output for the voltage.
Was voltage within the range?
Less than
0.2 V
Go to Step 7Go to Step 10
7At the sensor output terminal, backprobe with a DVM at
the sensor output
Was voltage within range?
Less than
0.2 V
Go to Step 9Go to Step 8
81. Locate open circuit or short circuit to ground line.
2. Repair the harness.
Is the action complete?
ÐVerify repairÐ

6E±337
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0452 ± Tank Pressure Sensor Low Voltage

 
StepNo Ye s Value(s) Action
91. Locate open circuit or short circuit to ground line.
2. Repair the harness.
Is the action complete?
ÐVerify repairÐ
10Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
On-Vehicle Service in
Powertrain Control Module and Sensors for
procedures.
And also refer to latest Service Bulletin.
Check to see if the Latest software is released or not.
And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.
Is the action complete?
ÐVerify repairÐ

6E±338
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0453 Fuel Tank Pressure Sensor (Vapor Pressure Sensor) High Voltage
060R200050
Circuit Description
The powertrain control module (PCM) monitors fuel tank
pressure sensor (Vapor pressure sensor) of the
Enhanced Evap system. When the tank pressure output
indicates high voltage , PCM will set DTC P0453.
Conditions for Setting the DTC

Tank sensor output is more than 4.9 volts for 12.5 sec.

100 test failures within a 200 tests.
Action Taken When the DTC Sets

The PCM will ON the MIL after second trip with
detected the fault.

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in Failure
Records data.
Conditions for Clearing the MIL/DTC

The PCM will turn the MIL ªOFFº on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.
A history DTC P0453 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

Info function or by disconnecting the PCM battery feed.
Diagnostic Aids
Check for the following conditions:

Open circuit of sensor ground line ± Inspect wiring
harness from PCM to the sensor. The PCM turns
P0453, and P0108 at the same time.

Open circuit or short circuit to 5 volt reference line ±
Inspect wiring harness from PCM to the sensor. The
PCM turns P0453 and P0108 at the same time.

Tank fuel pressure sensor malfunction may cause
P0453.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.

6E±339
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0453 ± Fuel Tank Pressure Sensor High Voltage

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªONº, engine ªOFFº, review and record
Tech 2 Failure Records Data.
2. Operate the vehicle within Failure Records
conditions as noted.
3. Using a Tech 2, monitor ªDTCº info for DTC P0453
until the DTC P0453 test runs. Note the result.
Does the Tech 2 indicates DTC P0452 or P0452/P0107
failed this ignition?
Ð
P0453/P0108
turn on
Go to
Step 3
P0452 turns on
Go to
Step 6
Refer to
Diagnostic
Aids
31. Ignition ªOFFº.
2. Disconnect connector at the PCM.
3. Ignition ªONº.
4. At the PCM connector, measure voltage with a
DVM at F54 and S37 terminals.
Was the voltage in range of voltage?
4±6 VGo to Step 4Go to Step 10
41. Ignition ªOFFº.
2. Connect the PCM connector to the PCM.
3. Disconnect sensor harness at fuel pressure sensor.
Measure voltage with a DVM at the end of the tank
pressure wiring between 5 V reference terminal and
sensor ground terminal.
Was the voltage within range?
4±6 V
For P0453 go
to
Step 6 and
for P0108, go
to diagnosis
section.
Go to Step 5
51. Locate open wiring of ground line from the PCM to
fuel tank pressure sensor.
2. Repair wiring harness.
Is the action complete?
ÐVerify repairÐ
61. Ignition ªONº.
2. At the PCM connector, backprobe with a DVM at the
sensor output for the voltage.
Was voltage within range?
More than
4.9 V
Go to Step 7Go to Step 10
7At the sensor output terminal, backprobe with a DVM at
the sensor output.
Was the voltage within range?
More than
4.9 V
Go to Step 9Go to Step 8
81. Locate open circuit or short circuit to ground line.
2. Repair the harness.
Is the action complete?
ÐVerify repairÐ

6E±340
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0453 ± Fuel Tank Pressure Sensor High Voltage

 
StepNo Ye s Value(s) Action
9Replace the tank pressure sensor.
Is the action complete?
ÐVerify repairÐ
10Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
On-Vehicle Service in
Powertrain Control Module and Sensors for
procedures.
And also refer to latest Service Bulletin.
Check to see if the Latest software is released or not.
And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.
Is the action complete?
ÐVerify repairÐ

6E±341
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0456 EVAP Very Small Leak
060R200050
Circuit Description
The evaporative system includes the following
components:

Fuel tank

EVAP canister vent solenoid

Fuel tank (vapor) pressure sensor

Vapor lines

Fuel cap

Evaporative emissions canister

Purge lines

EVAP canister purge solenoid
The evaporative leak detection diagnostic strategy is
based on applying vacuum to the EVAP system and
monitoring vacuum decay. The powertrain control
module(PCM)monitors vacuum level via the fuel tank
pressure sensor input. At an appropriate time, the
EVAP canister purge solenoid and the EVAP
canister vent solenoid are turned ªONº, allowing
engine vacuum to draw a very small look on the
entire evaporative emissions system. After the
desired vacuum level has been achieved, the EVAP
canister purge solenoid is turned ªOFFº, sealing the
system. A leak is detected by monitoring for a
decrease in vacuum level over a given time period,
all other variables remaining constant.
A very small leak in the system will cause DTC
P0456 to be set.
Conditions for setting the DTC

No MAP DTC's set.

No TPS DTC's set.

No IAT DTC's set.

No ECT DTC's set.

No tank pressure sensor DTC's set.

Baro is more than 70KPa.

Fuel level is between 40% and 80%.

Throttle angle is less than 3%.

Engine speed is less than 1200 RPM.

Vehicle speed is less than 5 mph (8 km/h).

A vacuum decay condition, indicating a very small leak,
is detected during the diagnostic test.
Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
fault is detected.

The PCM will store condition which were present when
the DTC was set as Freeze Frame and in the Failure
Records data.
Warm up cycles have occurred without a fault.
Conditions for Clearing the MIL/DTC

The PCM will turn the MIL ªOFFº on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.

6E±342
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

A history DTC P0456 will clear after 40 consecutive trip
cycle during which the warm up cycles have occurred
without a fault.

DTC P0456 can be cleared using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check for the following conditions:

Cracked or punctured EVAP canister.

Damaged source vacuum line, EVAP purge line, EVAP
vent hose or fuel tank vapor line. to wire connection.

Poor connection at PCM±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 to the
EVAP canister purge solenoid and the fuel tank
pressure sensor for an intermittent open or short
circuit.
Reviewing the Failure Records vehicle mileage since
the diagnostic test last failed may help determine
how often the condition that caused the DTC to be
set occurs.
This may assist in diagnosing the condition.

6E±343
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code(DTC)P0456 EVAP Very Small Leak

StepActionValue(s)Ye sNo
1Was the ªOn-Board(OBD)System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªOFFº.
2. Remove the fuel cap.
3. Ignition ªONº.
4. Observe ªFuel Tank Pressureº on the Tech 2.
Does the Tech 2 indicate ªFuel Tank Pressureº at the
specified value?
1.51VGo to Step 3
Go to Fuel
Tank
Pressure
System
31. Visually/physically check for the following
conditions:

Vent hose disconnected or damaged.

EVAP canister damaged.

Fuel cap damaged
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 4
41. Ignition ªONº, engine ªOFFº.
2. Install the fuel cap.
3. Review and record Tech 2 Failure Records data.
4. Operate the vehicle within Failure Records
conditions as noted.
5. Using theTech 2,monitor the ªDTCº info for DTC
P0456.
Does the Tech 2 indicate DTC P0456?
ÐGo to Step 5
Refer to
Diagnostic
Aids
51. Ignition ªONº, engine idling.
2. Observe ªFuel Tank Pressureº on the Tech 2.
Does the Tech 2 indicate ªFuel Tank Pressureº at the
specified value?
Ð
Refer to
Diagnostic
Aids
Go to Step 6
61. Ignition ªONº, engine idling.
2. Using theTech 2, command the EVAP canister vent
solenoid ªONº (closed)
3. Observe ªEVAP canister vent solenoid operationº
second value?
4. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 7
71. Visually/physically check for the following
conditions:

Disconnected or leaking fuel tank vapor line.

Disconnected or damaged EVAP purge line.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repair
Refer to
Diagnostic
Aids