6E±207
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0155
HO2S Heater Circuit Open Bank 2 Sensor 1
060R200054
Circuit Description
Heated oxygen sensors are used to minimize the amount
of time required for closed loop fuel control operation and
to allow accurate catalyst monitoring. The oxygen sensor
heater greatly decreases the amount of time required for
fuel control sensors Bank 1 HO2S 1 and Bank 2 HO2S 1
to become active. Oxygen sensor heaters are required
by post-catalyst monitor sensors to maintain a sufficiently
high temperature which allows accurate exhaust oxygen
content readings further from the engine.
The powertrain control module (PCM) will run the heater
test only after a cold start (determined by engine coolant
and intake air temperature at the time of start-up) and only
once during an ignition cycle. When the engine is started
the PCM will monitor the HO2S voltage. When the Bank
HO2S voltage indicates a sufficiently active sensor, the
PCM looks at how much time has elapsed since start-up.
If the PCM determines that too much time was required
for the Bank 2 HO2S 1 to become active, a DTC P0155
will set. The time it should take the HO2S to reach
operating temperature is based on the total amount of air
that has passed through the mass air flow (MAF) sensor
and into the engine (more total air flow = shorter time to
HO2S activity).
Conditions for Setting the DTC
No related DTCs.
The engine has been running for over 120 seconds.Ignition voltage is between 11 volts and 18 volts.
Heater signal is below 0.1A.
Bank 1 HO2S 2 voltage does not change more than
150 mV from the bias voltage (between
400 mV-500 mV) for a longer amount of time than it
should. The maximum amount of time to come up to
operating range is 120 seconds. This warm-up time
depends on the engine coolant temperature at start-up
and accumulated air flow since start-up.
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 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 P0155 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
DTC P0155 can be cleared by using the Tech 2 ªClear
infoº function or by disconnecting the PCM battery
feed.
6E±219
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0161 HO2S Heater Circuit Bank 2 Sensor 2
060R200054
Circuit Description
Heated oxygen sensors are used to minimize the amount
of time required for ªclosed loopº fuel control operation
and to allow accurate catalyst monitoring. The oxygen
sensor heater greatly decreases the amount of time
required for fuel control sensors Bank 1 HO2S 1 and Bank
2 HO2S 1 to become active. Oxygen sensor heaters are
required by post-catalyst monitor sensors to maintain a
sufficiently high temperature which allows accurate
exhaust oxygen content readings further from the engine.
The powertrain control module (PCM) will run the heater
test only after a cold start (determined by engine coolant
and intake air temperature at the time of start-up) and only
once during an ignition cycle. When the engine is started,
the PCM will monitor the HO2S voltage. When the Bank 2
HO2S 2 voltage indicates a sufficiently active sensor, the
PCM looks at how much time has elapsed since start-up.
If the PCM determines that too much time was required
for the Bank 2 HO2S 2 to become active, a DTC P0161
will set. The time it should take the HO2S to reach
operating temperature is based on the total amount of air
that has passed through the MAF sensor and into the
engine (more total air flow = shorter time to HO2S
activity).
Conditions for Setting the DTC
No related DTCs.
The engine has been running for over 120 seconds.Ignition voltage is between 11 volts and 18 volts.
Average mass air flow for the sample period is less
than 23 g/second.
Bank 2 HO2S 2 voltage does not change more than
150 mV from the bias voltage (between
400 mV-500 mV) for a longer amount of time than it
should. The maximum amount of time to come up to
operating range is 120 seconds. This warm-up time
depends on the engine coolant temperature at start-up
and accumulated air flow since start-up.
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 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 P0161 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
DTC P0161 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
6E±262
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0302 Cylinder Misfire Detected
Circuit Description
Misfire is monitored as a function of the combustion
quality (CQ) signals generated from the ignition current
sense system. Combustion signals represent the degree
of combustion in each cylinder. Misfire is detected when
the combustion signal is below a predetermined value.
This DTC P0302 will determine if the No.2 cylinder misfire
is occurring by monitoring the Combustion Quality.
Conditions for Setting the DTC
None of the following DTCs occur: TP sensor, MAF
sensor, vehicle speed sensor, ECT sensor.
The engine speed is between 600 and 6250 RPM.
The system voltage is between 11 and 16 volts.
The ECT indicates an engine temperature between
±7C (28F) and 110C (230F).
The throttle angle is steady and throttle change less
than 2% per 125 milliseconds.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
If the misfire is severe enough to cause possible
catalyst damage, the PCM will flash the MIL for as long
as the misfire remains at catalyst damaging levels.
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 ignition cycle in which the diagnostic has
been run and the fault condition is no longer present.
A history DTC P0302 will clear after 40 consecutive
ignition cycles occur without a fault.
DTC P0302 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:
System grounds ± Ensure all connections are clean
and properly tightened.
Injector ± Perform the injector coil/balance test to
locate a faulty injector that contributes to a lean
condition on the affected cylinder. In addition to the
above test, check the condition of the injector O-ring.
Faulty spark plug ± Check for a cracked insulator,
carbon tracking, incorrect gap, and worn electrodes.
Damaged or faulty ignition coil ± Check for cracks,
carbon tracking or other damage.
Substitute a known good coil ± Swap the ignition coils
and retest. If the misfire follows the coil, replace the
ignition coil.
DTC P0302 ± Cylinder Misfire Detected
StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Start the engine. Run the engine at idle.
2. Review and record Tech 2 Freeze Frame data.
3. Monitor ªMisfire Cur. #2º on the Tech 2.
Is ªMisfire Cur. #2º increasing (indicating a misfire
currently occurring)?
ÐGo to Step 4Go to Step 3
3Monitor ªMisfire Hist. #2º while operating the vehicle to
duplicate the conditions present when the DTC was set
(as defined by the Freeze Frame data recorded in Step
2).
Is ªMisfire Hist. #2º increasing (indicating a misfire
currently occurring)?
ÐGo to Step 4
Refer to
Diagnostic
Aids
41. Visually and physically inspect the vacuum hoses
for splits, kinks, and improper connections. Also,
inspect the intake manifold for a vacuum leak.
2. If a problem is found, repair it as necessary.
Did the inspection reveal a problem?
ÐVerify repairGo to Step 5
51. Install a spark tester at the spark plug end of the
cylinder #2 ignition coil.
2. Crank the engine while observing the spark tester.
A crisp, blue spark should be observed.
Is adequate spark present?
ÐGo to Step 8Go to Step 6
6E±304
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0404 EGR Open Stuck
060R200050
Circuit Description
The powertrain control module (PCM) 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 different from
commanded position. If the PCM detects a pintle position
signal indicates more than 15 points different between
current and commanded and more than 15 seconds, the
PCM will set DTC P0404.
Conditions for Setting the DTC
The engine is running.
Ignition voltage is between 11 and 16 volts.
Intake Air Temp is more than 3C (37.4F).
Desire EGR position is less than 3%.
The difference between desired EGR and current EGR
is less than 3%.
Difference EGR pintle position between current and
commanded position becomes more than 15% and
last more than 15 seconds, and this condition meets
three times in a trip. Then it trigger, the PCM lights on.
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 P0404 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:
Excessive carbon deposit on EGR valve shaft may
cause EGR stuck open or unsmooth operation. Those
carbon deposit may occur by unusual port operation.
Clean up carbon may make smooth function of EGR
valve.
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±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 70C (158F)
and 120C (248F).
Mass air flow is between 2.5 g/second and 10
g/second.
Engine speed is below 200 RPM.
Catalyst temperature is above 350C (662F).
The PCM determines that the catalyst's oxygen
storage capacity is below the acceptable threshold.
Intake Air Temperature is between ±10C (14F) and
70C (158F).
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 70C (158F)
and 120C (248F).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 350C (662F).
The PCM determines that the catalyst's oxygen
storage capacity is below the acceptable threshold.
Intake air temperature is between ±20C (4F) and
70C (158F).
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±324
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0444 EVAP Purge Control Circuit Open
060RY00398
Circuit Description
The canister purge solenoid valve is controlled by the
Power Train Control Module (PCM).The PCM monitors
vacuum level via the fuel tank pressure sensor input.
At an appropriate time, the EVAP canister purge solenoid
is ªON,º allowing engine vacuum to draw a small vacuum
on the entire evaporative emissions system.
Conditions for setting the DTC
The Ignition is ªONº.
Engine is running.
System voltage is between 11.5 volts and 16 volts.
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 P0444 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.DTC P0444 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:
Poor connections.
Mis routed harness.
Rubbed through wire insulation.
Broken wire inside the insulation.
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
EVAP purge solenoid 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. If DTC P0444 cannot be duplicated, the
information included in the Failure Records data can
be useful in determined vehicle mileage since the
DTC was last set.
If it is determined that the DTC occurs intermittently,
performing the DTC P0444 Diagnostic Chart may
isolate the cause of the fault.
6E±326
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0445 EVAP Purge Control Circuit Short
060RY00398
Circuit Description
The canister purge solenoid valve is controlled by the
Power Train Control Module (PCM). The PCM monitors
vacuum level via the fuel tank pressure sensor input.
At an appropriate time, the EVAP canister purge solenoid
is ªON,º allowing engine vacuum to draw a small vacuum
on the entire evaporative emissions system.
Conditions for setting the DTC
The Ignition is ªONº.
Engine is running.
System voltage is between 11.5 volts and 16 volts.
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 P0445 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.DTC P0445 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:
Poor connections.
Misrouted harness.
Rubbed through wire insulation.
Broken wire inside the insulation.
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
EVAP purge solenoid 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. If DTC P0445 cannot be duplicated, the
information included in the Failure Records data can
be useful in determined vehicle mileage since the
DTC was last set.
If it is determined that the DTC occurs intermittently,
performing the DTC P0445 Diagnostic Chart may
isolate the cause of the fault.