2002 ISUZU AXIOM air condition

6E±306
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0405 EGR Low Voltage
060R200050
Circuit Description
The powertrain control module (PCM) monitors the EGR
valve pintle position input to ensure that the valve
responds properly to command from the PCM. If current
pintle position voltage indicates less than 0.1 V and last
more than 10 seconds, then the PCM will set DTC P0405.
Conditions for Setting the DTC

Ignition voltage is between 11 and 16 volts.

Intake Air Temp is more than 3
C (37.4
F).

EGR pintle position is less than 2% and last more than
10 sec. Action taken when the DTC sets.
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 P0405 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 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±307
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0405 ± EGR 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 P0405
until the DTC P0405 test runs. Note the result.
Does the Tech 2 indicates DTC P0405 failed this
ignition?
ÐGo to Step 3
Refer to
Diagnostic
Aids
31. Disconnect the EGR valve harness connector.
2. Inspect the EGR valve and connectors for damaged
pin or terminals.
Were there any damaged pins or terminals?
ÐGo to Step 4Go to Step 5
4Repair the damaged pin or terminal.
Is the action complete?
ÐVerify repairÐ
51. Disconnect the EGR harness connector.
2. Ignition ªONº.
3. At the EGR valve, use a DVM to check the voltage
at the 5 volt reference wire (BLU/RED) and ground.
Did the DVM indicate the specified value?
4±6 VGo to Step 6Go to Step 7
61. Disconnect the EGR harness connector.
2. Measure resistance between terminal 5 volt
reference wire and ground.
Was resistance in range?
5±5.5 K
Go to Step 10Go to Step 17
71. Ignition ªONº.
2. At the PCM connector, backprobe with a DVM at the
5 volt reference for the EGR valve.
Did the DVM indicate the specified value?
4±6 VGo to Step 8Go to Step 18
8Repair the open 5 volt reference circuit.
Is the action complete?
ÐVerify repairÐ
9Repair the damaged sensor ground wire.
Is the action complete?
ÐVerify repairÐ
101. Disconnect the EGR harness
2. Use an ohmmeter to measure between the pintle
position pin and the sensor ground pin on the EGR
valve.
NOTE: J-35616 Connector Test Adapter Kit may be
useful for gaining access to the recessed pins on the
valve.
Was the ohmmeter reading approximately equal to the
specified value?
1 to 1.25 K
Go to Step 13Go to Step 17
111. Ignition ªONº.
2. Backprobe with a DVM to measure voltage at EGR
valve pintle position pin and sensor ground pin.
Was voltage in range?
Less than
0.1 V
Go to Step 17Go to Step 12

6E±309
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0406 EGR High Voltage
060R200050
Circuit Description
The powertrain control module (PCM) monitors the EGR
valve pintle position input to ensure that the valve
responds properly to command from the PCM. If current
pintle position voltage indicates more than 4.8 V and last
more than 10 seconds, then the PCM will set DTC P0406.
Conditions for Setting the DTC

Ignition voltage is between 11 and 16 volts.

Intake Air temp is more than 3
C (37.4
F).

EGR pintle position is more than 99% and last more
than 10 sec.
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:

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±310
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0406 ± EGR 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 P0406
until the DTC P0406 test runs. Note the result.
Does the Tech 2 indicates DTC P0406 failed this
ignition?
ÐGo to Step 3
Refer to
Diagnostic
Aids
31. Disconnect the EGR valve harness connector.
2. Inspect the EGR valve and connectors for damaged
pin or terminals.
Were there any damaged pins or terminals?
ÐGo to Step 4Go to Step 5
4Repair the damaged pin or terminal.
Is the action complete?
ÐVerify repair
Is the action
complete?
51. Disconnect the EGR harness connector.
2. Ignition ªONº.
3. At the EGR valve, use a DVM to check the voltage
at the 5 volt reference wire (BLU/RED).
Did the DVM indicate the specified value?
4±6 VGo to Step 8Go to Step 6
61. Ignition ªONº.
2. At the PCM connector, backprobe with a DVM at the
5 volt reference for the EGR valve.
Did the DVM indicate the specified value?
4±6 VGo to Step 7Go to Step 16
7Repair the open 5 volt reference circuit
Is the action complete?
ÐVerify repairÐ
81. Ignition ªOFFº
2. Disconnect the EGR harness.
3. Use a DVM to check for an resistance between 5 V
reference and Sensor Ground at EGR sensor
terminals.
NOTE: J-35616 Connector Test Adapter Kit may be
useful for gaining access to the recessed pins on the
valve.
Was the measured resistance in range?
5 to 5 K
Go to Step 9Go to Step 15
91. Ignition ªOFFº.
2. Disconnect the EGR harness.
3. Use a DVM to check for an resistance between
Sensor Ground and Signal Wire at EGR sensor
terminal.
Is there an open circuit?
ÐGo to Step 15Go to Step 10
101. Ignition ªOFFº.
2. Disconnect the EGR harness at PCM connector.
3. Use a DVM to check for shorted wire between S37
and F53.
Is there a shorted wire?
ÐGo to Step 14Go to Step 11

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±313
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
will require three or more 50-sample tests to report a
failure.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
7. Difficulty completing the DTC P0420 ªStatus This
Ignº, test may be encountered in areas where test
conditions cannot be maintained easily, especially in
urban areas. To minimize the amount of driving
required to complete the DTC P0420 ªStatus This
Ignº, test, use the following procedure:

Allow the engine to warm up completely.

With the vehicle in ªParkº, monitor mass air flow on
the Tech 2 and hold part throttle to maintain a
reading of over 12 g/second for at least 2 minutes.
This will achieve the ªwarm catalystº required for
running the test.

Operate the vehicle in second or third gear to remain
in the DTC P0420 test conditions described in
ªConditions for Setting the DTCº as much as
possible. If you must stop the vehicle, maintain the
ªwarm catalystº criteria as follows:
± Place the vehicle in ªParkº or ªNeutralº,
± Hold part throttle to maintain a mass air flow
reading of over 15 g/second for the duration of the
stop.

6E±314
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0420 ± TWC System Low Efficiency Bank 1

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Are any other DTCs set (such as P0140)?
Ð
Diagnose
other DTC(s)
first
Go to Step 3
31. Visually and physically inspect the three-way
catalytic converter for damage. Check for the
following:

dents

severe discoloration caused by excessive
temperatures

holes

internal rattle caused by damaged catalyst
2. Also, ensure that the three-way catalytic converter
is a proper original equipment manufacturer part.
Did your inspection reveal a problem?
ÐGo to Step 6Go to Step 4
41. Visually and physically inspect the exhaust system
between the three-way catalytic converter and the
rear converter flange for leaks, damage, and loose
or missing hardware.
2. If a problem is found, repair as necessary.
Did your inspection reveal a problem?
Ð
Go to Step 7
to verify
repair
Go to Step 5
51. Visually and physically inspect the Bank 1 HO2S 2.
2. Ensure that the Bank 1 HO2S 2 is secure and that
the pigtail and wiring harness is not contacting the
exhaust pipe or is not otherwise damaged.
3. If a problem is found, repair as necessary.
Did your inspection reveal a problem?
Ð
Go to Step 7
to verify
repair
Go to Step 6
6Replace the three-way catalytic converter.
NOTE: Check for conditions which may cause catalyst
damage (refer to
Diagnostic Aids).
Is the action complete?
Ð
Go to Step 7
to verify
repair
Ð
71. Review and record the Tech 2 Failure Records data.
2. Clear DTC P0420.
3. Start the engine and allow it to warm up until the
engine coolant temperature monitored on the Tech
2 is above the specified value.
4. Run the engine to maintain the specified mass air
flow range for at least 2 minutes.
5. Operate the vehicle to maintain DTC P0420 test
conditions (refer to
DTC Test Description in
Diagnostic Support for detailed instructions).
6. Using a Tech 2, monitor ªDTCº info for DTC P0420
until the DTC P0420 test runs.
7. Note the test result.
Does the Tech 2 indicate DTC P0420 passed this
ignition?
Engine
coolant temp:
greater than
60
C
(140
F).
Mass air flow:
between 8
g/second and
50 g/second
Complete
repair. If a
driveability
symptom still
exists, refer
to
Symptoms.
Go to the
Diagnostic
Aids

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.