2002 ISUZU AXIOM turn signal

6E±312
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0420 TWC System Low Efficiency Bank 1
T321075
Circuit Description
To control emissions of hydrocarbons (HC), carbon
monoxide (CO), and oxides of nitrogen (NOx), a
three-way catalyst (TWC) is used. The catalyst promotes
a chemical reaction which oxidizes the HC and CO
present in the exhaust gas, converting them into
harmless water vapor and carbon dioxide. The catalyst
also reduces NOx, converting it to nitrogen. The
powertrain control module (PCM) has the ability to
monitor this process using the Bank 1 HO2S 1 and the
Bank 1 HO2S 2 heated oxygen sensors. The Bank 1
HO2S 1 sensor produces an output signal which indicates
the amount of oxygen present in the exhaust gas entering
the three-way catalytic converter. The Bank 1 HO2S 2
sensor produces an output signal which indicates the
oxygen storage capacity of the catalyst; this in turn
indicates the catalyst's ability to convert exhaust gases
efficiently. If the catalyst is operating efficiently, the Bank
1 HO2S 1 signal will be far more active than that produced
by the Bank 1 HO2S 2 sensor. If the PCM detects a level
of Bank 1 HO2S 2 activity that indicates the catalyst is no
longer operating efficiently, DTC P0420 will be set.
Conditions for Setting the DTC

No related DTCs.

The engine is operating in ªclosed loopº,

Engine air load is below 99%.

Engine coolant temperature is between 70
C (158
F)
and 120
C (248
F).

Mass air flow is between 2.5 g/second and 10
g/second.

Engine speed is below 200 RPM.

Catalyst temperature is above 350
C (662
F).

The PCM determines that the catalyst's oxygen
storage capacity is below the acceptable threshold.

Intake Air Temperature is between ±10
C (14
F) and
70
C (158
F).

Throttle angle is less than 1.5%.
Barometric Pressure is more than 72 kPa.
Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
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 P0420 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0420 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:

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 for
damage. If the harness appears to be OK, observe the
display on the Tech 2 while moving connectors and
wiring harnesses related to the sensor. A change in the
display will indicate the location of the fault.
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.
The ªTWC Monitor Test Counterº displayed on the Tech 2
may be used to monitor the progress of the TWC
diagnostic. To complete the TWC diagnostic with a good
catalyst, the counter must be allowed to increment to 49
samples and roll over to 0 at least twice. A failed catalyst

6E±315
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0430 TWC System Low Efficiency Bank 2
T321075
Circuit Description
To control emissions of hydrocarbons (HC), carbon
monoxide (CO), and oxides of nitrogen (NOx), a
three-way catalyst (TWC) is used. The catalyst promotes
a chemical reaction which oxidizes the HC and CO
present in the exhaust gas, converting them into
harmless water vapor and carbon dioxide. The catalyst
also reduces NOx, converting it to nitrogen. The
powertrain control module (PCM) has the ability to
monitor this process using the Bank 2 HO2S 1 and the
Bank 2 HO2S 2 heated oxygen sensors. The Bank 2
HO2S 1 sensor produces an output signal which indicates
the amount of oxygen present in the exhaust gas entering
the three-way catalytic converter. The Bank 2 HO2S 2
sensor produces an output signal which indicates the
oxygen storage capacity of the catalyst; this in turn
indicates the catalyst's ability to convert exhaust gases
efficiently. If the catalyst is operating efficiently, the Bank
2 HO2S 1 signal will be far more active than that produced
by the Bank 2 HO2S 2 sensor. If the PCM detects a level
of Bank 2 HO2S 2 activity that indicates the catalyst is no
longer operating efficiently, DTC P0430 will be set.
Conditions for Setting the DTC

No related DTCs.

The engine is operating in ªclosed loopº.

Engine air load is below 99%.

Engine coolant temperature is between 70
C (158
F)
and 120
C (248
F).
Mass air flow is between 2.5 g/second and 10
g/second.

Change in engine load is below 8%.

Engine speed is below 200 RPM.

Catalyst temperature is above 350
C (662
F).

The PCM determines that the catalyst's oxygen
storage capacity is below the acceptable threshold.

Intake air temperature is between ±20
C (4
F) and
70
C (158
F).

Throttle angle is less than 1.5%.

Barometric Pressure is more than 72 kPa.
Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
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 P0430 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0430 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.

6E±328
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0446 EVAP Canister Vent Control Malfunction
060RY00398
Circuit Description
The evaporative system includes the following
components:

Fuel tank

EVAP canister vent solenoid

Fuel tank (vapor) pressure sensor

Fuel pipes and hoses

Vapor lines

Fuel cap

Evaporative emissions canister

Purge lines

EVAP canister purge solenoid
An incorrect fuel tank pressure sensor signal is detected
by monitoring fuel tank pressure when the key is first
turned ªONº during a cold start. If the fuel tank pressure
signal is out of range, DTC P0446 will set. A restricted or
blocked EVAP vent path is detected by monitoring fuel
tank pressure during normal operation (EVAP canister
vent solenoid open, EVAP canister purge solenoid
normal). With the EVAP canister vent solenoid open,
vacuum level in the system should be very low unless the
vent path is blocked. A blockage can be caused by the
following condition:

Faulty EVAP canister vent solenoid (stuck closed).

Plugged, kinked or pinched vent hose.

Shorted EVAP canister vent solenoid driver circuit.

Plugged evaporative canister.If any of these conditions are present, DTC P0446 will set.Conditions for Setting the DTC

No TP sensor, ECT sensor, Tank pressure sensor, IAT
sensor, or MAP sensor DTCs set.

Start-up engine coolant temperature and start-up
intake air temperature are more than 4
C (39
F) but
less than 34
C(93
F).

Start-up engine coolant temperature is not more than
7
C (13
F) greater than start-up intake air
temperature.

Fuel tank level is between 15% and 85%.

BARO is greater than 70 kPa.
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 set as Freeze Frame and 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 P0446 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

6E±346
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0462 Fuel Level Sensor Circuit±Low Voltage
060RY00163
Circuit Description
The fuel level sensor is an important input to powertrain
control module (PCM) for the enhanced evaporative
system diagnostic. Fuel level information is needed for
the PCM to know the volume of fuel in the tank. The fuel
level affects the rate of change in air pressure in the
evaporative system. Several of the enhanced
evaporative system diagnostic sub-tests are dependent
upon correct fuel level information. The diagnostic will not
run when the tank is more than 85% or less than 15% full.
Fuel level DTCs should be diagnosed before other
evaporative system DTCs because they can cause other
DTCs to be set.
The sending unit is a float in the fuel tank which moves a
wiper arm across a variable resistor. Low fuel level
causes high resistance in the sending unit, and this is
recognized by the PCM because the circuit operates at a
corresponding low voltage. When the circuit is
continuously open or has a high resistance connection,
DTC P0462 is set.
Conditions for Setting the DTC

Fuel tank level ªslosh testº is completed.

Fuel tank level ªmain testº is completed.

Fuel tank level data is valid.

Fuel tank level signal is less than a specified value.

There are 100 test failures within a 200-test sample.
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 the
Failure Records data.
Conditions for Clearing the DTC

The PCM will turn the MIL ªOFFº after three
consecutive trips without a fault condition present. A
history DTC will be cleared if no fault conditions have
been detected for 40 warm-up cycles (engine coolant
temperature has risen 4
C (40
F) from the start-up
ECT, and ECT exceeds 71
C (160
F) during that
same ignition cycle).

DTC P0462 can be cleared by using the scan tool
ªClear Infoº function or by disconnecting the PCM
battery feed.
Diagnostic Aids

Damaged harness±Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
fuel level display on the scan tool while moving
connectors and wiring harnesses related to the sensor.
A change in the display will indicate the location of the
fault.

6E±349
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0463 Fuel Level Sensor Circuit±High Voltage
060RY00163
Circuit Description
The fuel level sensor is an important input to powertrain
control module (PCM) for the enhanced evaporative
system diagnostic. Fuel level information is needed for
the PCM to know the volume of fuel in the tank. The fuel
level affects the rate of change in air pressure in the
evaporative system. Several of the enhanced
evaporative system diagnostic sub-tests are dependent
upon correct fuel level information. The diagnostic will not
run when the tank is more than 85% or less than 15%, full.
Fuel level DTCs should be diagnosed before other
evaporative system DTCs because they can cause other
DTCs to be set.
The sending unit is a float in the fuel tank which moves a
wiper arm across a variable resistor. High fuel level
causes low resistance in the sending unit. This is
recognized by the PCM because the circuit operates at a
corresponding high voltage. When the circuit is
continuously shorted to a voltage source greater than a
specified value, or when the 5 volt signal is shorted to
ground, DTC P0463 is set.
Conditions for Setting the DTC

Fuel tank level ªslosh testº is completed.

Fuel tank level ªmain testº is completed.

Fuel tank level data is valid.

Fuel tank level signal is greater than a specified value.

There are 100 test failures within a 200-test sample.
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 the
Failure Records data.
Conditions for Clearing the DTC

The PCM will turn the MIL ªOFFº after three
consecutive trips without a fault condition present. A
history DTC will be cleared if no fault conditions have
been detected for 40 warm-up cycles (engine coolant
temperature has risen 4
C (40
F) from the start-up
ECT, and ECT exceeds 71
C (160
F) during that
same ignition cycle) or the scan tool clearing function
has been used.

DTC P0463 can be cleared by using the scan tool
ªClear Infoº function or by disconnecting the PCM
battery feed.

6E±353
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0502 VSS Circuit Low Input
060R200056
Circuit Description
The vehicle speed sensor has a magnet rotated by the
transmission output shaft. Attached to the sensor is a hall
effect circuit the interacts with the magnetic field treated
by the rotating magnet. A 12-volt operating supply for the
speed sensor hall circuit is supplied from the meter fuse.
The VSS pulses to ground the 9-volt signal sent from the
powertrain control module (PCM) on the reference circuit.
The PCM interprets vehicle speed by the number of
pulses to ground per second on the reference circuit.
Conditions for Setting the DTC

Engine is running.

Engine speed is between 1800 RPM and 2500 RPM.

Throttle angle is between 10% and 40%.

Engine load is greater than 50 kPa.

PCM detects no VSS signal for 12.5 seconds over a
period of 15 seconds.
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 the
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 P0502 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0502 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
10. To avoid backprobing the VSS and possibly
damaging a seal or terminal, the VSS output can be
tested at the point where the transmission harness
connects to the engine harness. Power and ground
are applied by jumpers to the VSS through the
connectors which are located to the rear of the air
cleaner assembly. The VSS signal is monitored
with a DVM as the rear driveshaft turns. The
wheels can be turned to rotate the driveshaft, or in
2-wheels-drive vehicles the driveshaft can be turned
directly.

6E±366
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0565 Cruise Main Switch Circuit Error
060R100094
Circuit Description
The cruise control keeps the vehicle running at a fixed
speed until a signal canceling this fixed speed is received.
When the main switch is turned on with the vehicle in the
running mode, the battery voltage is applied to power train
control module(PCM). When a signal from the control
switch is input to PCM while the vehicle is in this state, the
cruise control system is activated. Also, while the PCM is
operating, the ªCRUISE MAINº indicator light in the meter
assembly lights up.
Conditions for setting the DTC

The Ignition is ªON''.

Engine is running.

System voltage is between 11.5 volts and 16 volts.

The switch contact remains on for 15 seconds or more.

Noises are generated by poor switch contact 60 times
within 1 second.
Action Taken When the DTC Sets

The PCM will not illuminate the malfunction indicator
lamp (MIL).

The PCM will store conditions which were present
when the DTC was set in the Failure Records data only.
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 P0565 will clear after 40 consecutive trip
cycle during which the warm up cycles have occurred
without a fault.

DTC P0565 can be cleared using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
An intermittent may be caused by the following:

6E±368
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0566 Cruise Cancel Switch Circuit Error
060R100094
Circuit Description
The cruise control keeps the vehicle running at a fixed
speed until a signal canceling this fixed speed is received.
When the main switch is turned on with the vehicle in the
running mode, the battery voltage is applied to powertrain
control module(PCM). When a signal from the control
switch is input to PCM while the vehicle is in this state, the
cruise control system is activated. Also, while the PCM is
operating, the ªCRUISE MAINº indicator light in the meter
assembly lights up.
When the cancel switch is ªONº, cruise system is ªOFFº.
Conditions for setting the DTC

The Ignition is ªONº.

Engine is running.

System voltage is between 11.5 volts and 16 volts.

The switch contact remains on for 40 seconds or more.
Noises are generated by poor switch contact 100 times
within 1.6 seconds.
Action Taken When the DTC Sets

The PCM will not illuminate the malfunction indicator
lamp (MIL).

The PCM will store conditions which were present
when the DTC was set in the Failure Records data only.
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 P0566 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.