6E±211
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Aids
Check for the following conditions:
Heated oxygen sensor wiring ± The sensor pigtail may
be mispositioned and contacting the exhaust system.
Poor PCM to engine grounds.
Fuel pressure ± A condition which causes a lean
exhaust can cause DTC P0157 to set. The system will
go lean if pressure is too low. The PCM can
compensate for some decrease. However, if fuel
pressure is too low, a DTC P0157 may be set. Refer
to
Fuel System Diagnosis.
Lean injector(s) ± Perform ªInjector Balance Testº.
Vacuum leaks ± Check for disconnected or damaged
vacuum hoses and for vacuum leaks at the intake
manifold, throttle body, EGR system, and PCV system.
Exhaust leaks ± An exhaust leak may cause outside air
to be pulled into the exhaust gas stream past the
HO2S, causing the DTC P0157 to set. Check for
exhaust leaks near the Bank 1 HO2S 2 sensor.
MAF sensor ± The system can go lean if the MAF
sensor signal indicates an engine airflowmeasurement that is not correct. Disconnect the MAF
sensor to see if the condition is corrected. If so, replace
the MAF sensor.
Fuel contamination ± Water, even in small amounts,
can be delivered to the fuel injectors. The water can
cause a lean exhaust to be indicated. Excessive
alcohol in the fuel can also cause this condition. Refer
to
Fuel System Diagnosis for the procedure to check
for fuel contamination.
If none of above conditions are present, replace the
affected HO2S 2.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. DTC P0157 failing during operation may indicate a
condition described in the ªDiagnostic Aidsº above.
If the DTC P0157 test passes while the Failure
Records conditions are being duplicated, an
intermittent condition is indicated.
DTC P0157 ± HO2S Circuit Low Voltage Bank 2 Sensor 2
StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Install the Tech 2.
2. Run the engine at operating temperature.
3. Operate the vehicle within the parameters specified
under ªConditions for Setting the DTCº criteria
included in Diagnostic Support.
4. Using a Tech 2, monitor Bank 2 HO2S 2 voltage.
Does the Bank 2 HO2S 2 voltage remain below the
specified value?
22 mVGo to Step 4Go to Step 3
31. Ignition ªONº, engine ªOFFº.
2. Review and record Tech 2 Failure Records data and
note parameters.
3. Operate the vehicle within Failure Records
conditions as noted.
4. Using a Tech 2, monitor ªDTCº info for DTC P0157
until the DTC P0157 test runs.
5. Note the test result.
Does the Tech 2 indicate DTC P0157 failed this
ignition?
ÐGo to Step 4
Refer to
Diagnostic
Aids
41. Turn the ignition ªOFFº.
2. Disconnect the PCM.
3. Check the Bank 2 HO2S 2 high and low signal
circuits for a short to ground or a short to the heater
ground circuit.
Were Bank 2 HO2S 2 signal circuits shorted?
ÐGo to Step 5Go to Step 6
5Repair the Bank 1 HO2S 2 signal circuit.
Is the action complete?
ÐVerify repairÐ
6E±213
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0158 HO2S Circuit High Voltage Bank 2 Sensor 2
060R200054
Circuit Description
To control emissions of hydrocarbons (HC), carbon
monoxide (CO), and oxides of nitrogen (NOx), a
three-way catalytic converter is used. The catalyst within
the converter 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 Bank 2
HO2S 2 signal voltage remains excessively high for an
extended period of time, DTC P0158 will be set.
Conditions for Setting the DTC
No related DTCs.
Engine is operating in ªclosed loopº.
ªClosed loopº commanded air/fuel ratio is between
14.5 and 14.8.Engine coolant temperature is above 60C (140F).
Bank 2 HO2S 2 signal voltage remains above 952 mV
during normal ªclosed loopº operation for a total of 106
seconds over a 125-second period.
OR
Bank 2 HO2S 2 signal voltage remains above 500 mV
during deceleration fuel cutoff mode operation for up to
3 seconds.
Action Taken When the DTC Sets
The PCM will ON the MIL after second trip with
detected 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 P0158 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
DTC P0158 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
6E±216
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0160 HO2S Circuit Insufficient Activity Bank 2 Sensor 2
060R200054
Circuit Description
To control emissions of hydrocarbons (HC), carbon
monoxide (CO), and oxides of nitrogen (NOx), a
three-way catalytic converter is used. The catalyst within
the converter 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 Bank 2
HO2S 2 signal voltage remains between 400 mV and
500 mV for an extended period of time, DTC P0160 will be
set.
Heated Oxygen sensors are used to minimize the amount
of time required for ªclosed loopº fuel control operation
and allow accurate catalyst monitoring. The oxygen
sensor heater greatly decreases the amount of time
required for fuel control sensors Bank 1 HO2S 1 and Bank2 HO2S 1 to become active. Oxygen sensor heaters are
required by post-catalyst monitor sensors to maintain a
sufficiently high temperature for accurate exhaust oxygen
content readings further from the engine.
Conditions for Setting the DTC
No related DTCs.
Battery voltage is above 10 volts.
The engine has been running for over 5 seconds.
Oxygen sensor heater is functioning properly.
Engine is in ªclosed loopº operation.
Bank 2 HO2S 2 signal voltage remains between
426 mV and 474 mV for a total of 106 seconds over a
125-second period of time.
Action Taken When the DTC Sets
The PCM will ON the MIL after second trip with
detected 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 P0160 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
6E±222
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0171 Fuel Trim System Lean Bank 1
060R200054
Circuit Description
To provide the best possible combination of driveability,
fuel economy, and emission control, a ªclosed loopº
air/fuel metering system is used. While in ªclosed loopº,
the powertrain control module (PCM) monitors the Bank 1
HO2S 1 and Bank 2 HO2S 1 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 PCM 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 PCM is reducing the amount of fuel
delivered. If an excessively lean condition is detected on
Bank 1, the PCM will set DTC P0171.
The PCM's maximum authority to control long term fuel
trim allows a range between ±15% (automatic
transmission) or ±12% (manual transmission) and +20%.
The PCM monitors fuel trim under various engine
speed/load fuel trim cells before determining the status of
the fuel trim diagnostic.
Conditions for Setting the DTC
None of the following: EGR DTCs, HO2S DTCs,
(response, transition, open, low volts, no activity), MAF
DTCs, TP sensor DTCs, MAP DTCs, IAT DTCs,
canister purge DTCs, EVAP DTCs, injector circuit
DTCs, or misfire DTCs. Engine coolant temperature is between 6C (42.8F)
and 105C (221F).
Intake air temperature is between ±40C (±40F) and
120C (248F).
Manifold absolute pressure is between 24 kPa and 99
kPa.
Throttle angle is steady below 95%.
Vehicle speed is below 136 km/h (85 mph).
Engine speed is between 400 and 6,000 RPM.
Barometric pressure is greater than 72.5 kPa.
Mass air flow is between 2 g/second and 200 g/second.
Ignition voltage is above 9.5 volts.
Fuel system is in ªclosed loopº.
Canister purge duty cycle is greater than 0% if on.
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 P0171 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
6E±226
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0172 Fuel Trim System Rich Bank 1
060R200054
Circuit Description
To provide the best possible combination of driveability,
fuel economy, and emission control, a ªclosed loopº
air/fuel metering system is used. While in ªclosed loopº,
the powertrain control module (PCM) monitors the Bank 1
heated oxygen sensors (HO2S) 1 and Bank 2 HO2S 1
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 PCM 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 PCM is
reducing the amount of fuel delivered. If an excessively
rich condition is detected on Bank 1, the PCM will set DTC
P0172.
The PCM's maximum authority to control long term fuel
trim allows a range between ±15% (automatic
transmission) or ±12 (manual transmission) and +20%.
The PCM's maximum authority to control short term fuel
trim allows a range between ±11% and +20%. The PCM
monitors fuel trim under various engine speed/load fuel
trim cells before determining the status of the fuel trim
diagnostic.
Conditions for Setting the DTC
None of the following was set: EGR DTCs, HO2S
DTCs, (response, transition, open, low volts, no
activity), MAF DTCs, TPS DTCs, MAP DTCs, IATDTCs, canister purge DTCs, EVAP DTCs, injector
circuit DTCs, or misfire DTCs.
Engine coolant temperature is between 6C (42.8F)
and 105C (221F).
Intake air temperature is between ±40C (±40F) and
120C (248F).
Manifold absolute pressure is between 24 kPa and 99
kPa.
Throttle angle is steady below 95%.
Vehicle speed is below 136 km/h (85 mph).
Engine speed is between 400 and 6,000 RPM.
Barometric pressure is greater than 72.5 kPa.
Mass air flow is between 2 g/second and 200 g/second.
Ignition voltage is above 9.5 volts.
Fuel system is in ªclosed loopº.
Canister purge duty cycle is greater than 0%, if ªONº.
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.
6E±230
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0174 Fuel Trim System Lean Bank 2
060R200054
Circuit Description
To provide the best possible combination of driveability,
fuel economy, and emission control, a ªclosed loopº
air/fuel metering system is used. While in ªclosed loopº,
the powertrain control module (PCM) monitors the Bank 1
HO2S 1 and Bank 2 HO2S 1 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 PCM 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 PCM is reducing the amount of fuel
delivered. If an excessively lean condition is detected on
Bank 2, the PCM will set DTC P0174.
The PCM's maximum authority to control long term fuel
trim allows a range between ±15%(automatic
transmission) or ±12%(manual transmission) and +20%.
The PCM monitors fuel trim under various engine
speed/load fuel trim cells before determining the status of
the fuel trim diagnostic.
Conditions for Setting the DTC
None of the following DTCs are set: idle system, EGR,
HO2S, (response, transition, open, low volts, no
activity), MAF, TP sensor, MAP, IAT, canister purge,
EVAP, injector circuit, or misfire.
Engine coolant temperature is between 6C (42.8F)
and 105C (221F).Intake air temperature is between ±40C (±40F) and
120C (248F).
Manifold absolute pressure is between 24 kPa and 99
kPa.
Throttle angle is steady between 3 and 95%.
Vehicle speed is below 136 km/h (85 mph).
Engine speed is between 400 and 6,000 RPM.
Barometric pressure is greater than 72.5 kPa.
Mass air flow is between 2 g/second and 200 g/second.
Ignition voltage is above 9.5 volts.
Fuel system is in ªclosed loopº.
Canister purge duty cycle is greater than 0%, if ªONº.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
failure 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 P0174 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
DTC P0174 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
6E±234
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0175 Fuel Trim System Rich Bank 2
060R200054
Circuit Description
To provide the best possible combination of driveability,
fuel economy, and emission control, a ªclosed loopº
air/fuel metering system is used. While in ªclosed loopº,
the powertrain control module (PCM) monitors the Bank 1
HO2S 1 and Bank 2 HO2S 1 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 PCM 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 PCM is reducing the amount of fuel
delivered. If an excessively rich condition is detected on
Bank 2, the PCM will set DTC P0175.
The PCM's maximum authority to control long term fuel
trim allows a range between ±15%(automatic
transmission) or ±12%(manual transmission) and +20%.
The PCM's maximum authority to control short term fuel
trim allows a range between ±11% and +20%. The PCM
monitors fuel trim under various engine speed/load fuel
trim cells before determining the status of the fuel trim
diagnostic.
Conditions for Setting the DTC
None of the following DTCs are set: idle system, EGR,
HO2S, (response, transition, open, low volts, noactivity), MAF, TPS, MAP, IAT, canister purge, EVAP,
injector circuit, or misfire.
Engine coolant temperature is between 6C (42.8F)
and 105C (221F).
Intake air temperature is between ±40C (±40F) and
120C (248F).
Manifold absolute pressure is between 24 kPa and 99
kPa.
Throttle angle is steady between 3 and 95%.
Vehicle speed is below 136 km/h (85 mph).
Engine speed is between 400 and 6,000 RPM.
Barometric pressure is greater than 72.5 kPa.
Mass air flow is between 2 g/second and 200 g/second.
Ignition voltage is above 9.5 volts.
Fuel system is in ªclosed loopº.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
failure 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.
6E±238
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0201 Injector 1 Control Circuit
060R200023
Circuit Description
The powertrain control module (PCM) has six individual
injector driver circuits. Each controls an injector. When a
driver circuit is grounded by the PCM, the injector is
activated. The PCM monitors the current in each driver
circuit. The voltage on each driver is monitored to detect
a fault. If the voltage is not what the PCM 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.
Conditions for Setting the DTC
The battery voltage is more than 9 volts.
Engine speed is more than 700 rpm.
The engine is turning, determined by 58X crankshaft
position input signal.
The injector voltage does not equal the ignition voltage
when the injector is commanded ªOFFº or the injector
voltage does not equal 0 volts when the injector is
commanded ªONº.
The above conditions are met for 5 seconds.
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 ªOFFº the MIL on the third
consecutive trip cycle in which the diagnostic has been
run and the fault is no longer present.
A history DTC P0201 will clear after 40 consecutive
warm-up cycles occur without a fault.
DTC P0201 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
An injector driver circuit that is open or shorted to voltage
will cause a DTC P0201 to set. It will also cause a misfire
due to an inoperative injector. A misfire DTC will also be
set indicating which cylinder is inoperative.
Long term and short term fuel trims that are excessively
high or low are a good indication that an injector is faulty.
Use Fuel Injector Coil Test Procedure to check for faulty
injectors.