2002 ISUZU AXIOM ESP

6E±34
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
dissatisfaction. The following list of non-vehicle faults
does not include every possible fault and may not apply
equally to all product lines.
Fuel Quality
Fuel quality is not a new issue for the automotive industry,
but its potential for turning on the MIL (ªCheck Engineº
lamp) with OBD II systems is new.
Fuel additives such as ªdry gasº and ªoctane enhancersº
may affect the performance of the fuel. If this results in an
incomplete combustion or a partial burn, it will show up as
a Misfire DTC P0300. The Reed Vapor Pressure of the
fuel can also create problems in the fuel system,
especially during the spring and fall months when severe
ambient temperature swings occur. A high Reed Vapor
Pressure could show up as a Fuel Trim DTC due to
excessive canister loading. High vapor pressures
generated in the fuel tank can also affect the Evaporative
Emission diagnostic as well.
Using fuel with the wrong octane rating for the vehicle
may cause driveability problems. Many of the major fuel
companies advertise that using ªpremiumº gasoline will
improve the performance of the vehicle. Most premium
fuels use alcohol to increase the octane rating of the fuel.
Although alcohol-enhanced fuels may raise the octane
rating, the fuel's ability to turn into vapor in cold
temperatures deteriorates. This may affect the starting
ability and cold driveability of the engine.
Low fuel levels can lead to fuel starvation, lean engine
operation, and eventually engine misfire.
Non-OEM Parts
All of the OBD II diagnostics have been calibrated to run
with OEM parts. Something as simple as a
high-performance exhaust system that affects exhaust
system back pressure could potentially interfere with the
operation of the EGR valve and thereby turn on the MIL
(ªCheck Engineº lamp). Small leaks in the exhaust
system near the post catalyst oxygen sensor can also
cause the MIL (ªCheck Engineº lamp) to turn on.
Aftermarket electronics, such as transceivers, stereos,
and anti-theft devices, may radiate EMI into the control
system if they are improperly installed. This may cause a
false sensor reading and turn on the MIL (ªCheck Engineº
lamp).
Environment
Temporary environmental conditions, such as localized
flooding, will have an effect on the vehicle ignition system.
If the ignition system is rain-soaked, it can temporarily
cause engine misfire and turn on the MIL (ªCheck Engineº
lamp).
Refueling
A new OBD II diagnostic was introduced in 1996 on some
vehicles. This diagnostic checks the integrity of the entire
evaporative emission system. If the vehicle is restarted
after refueling and the fuel cap is not secured correctly,
the on-board diagnostic system will sense this as a
system fault and turn on the MIL (ªCheck Engineº lamp)
with a DTC P0440.Vehicle Marshaling
The transportation of new vehicles from the assembly
plant to the dealership can involve as many as 60 key
cycles within 2 to 3 miles of driving. This type of operation
contributes to the fuel fouling of the spark plugs and will
turn on the MIL (ªCheck Engineº lamp) with a P0300
Misfire DTC.
Poor Vehicle Maintenance
The sensitivity of OBD II diagnostics will cause the MIL
(ªCheck Engineº lamp) to turn on if the vehicle is not
maintained properly. Restricted air filters, fuel filters, and
crankcase deposits due to lack of oil changes or improper
oil viscosity can trigger actual vehicle faults that were not
previously monitored prior to OBD II. Poor vehicle
maintenance can't be classified as a ªnon-vehicle faultº,
but with the sensitivity of OBD II diagnostics, vehicle
maintenance schedules must be more closely followed.
Related System Faults
Many of the OBD II system diagnostics will not run if the
PCM detects a fault on a related system or component.
One example would be that if the PCM detected a Misfire
fault, the diagnostics on the catalytic converter would be
suspended until Misfire fault was repaired. If the Misfire
fault was severe enough, the catalytic converter could be
damaged due to overheating and would never set a
Catalyst DTC until the Misfire fault was repaired and the
Catalyst diagnostic was allowed to run to completion. If
this happens, the customer may have to make two trips to
the dealership in order to repair the vehicle.
Emissions Control Information Label
The engine compartment ªVehicle Emissions Control
Information Labelº contains important emission
specifications and setting procedures. In the upper left
corner is exhaust emission information. This identifies
the emission standard (Federal, California, or Canada) of
the engine, the displacement of the engine in liters, the
class of the vehicle, and the type of fuel metering system.
There is also an illustrated emission components and
vacuum hose schematic.
This label is located in the engine compartment of every
vehicle. If the label has been removed it should be
replaced. It can be ordered from Isuzu Dealership.
Visual / Physical Engine Compartment
Inspection
Perform a careful visual and physical engine
compartment inspection when performing any diagnostic
procedure or diagnosing the cause of an emission test
failure. This can often lead to repairing a problem without
further steps. Use the following guidelines when
performing a visual/physical inspection:

Inspect all vacuum hoses for pinches, cuts,
disconnections, and proper routing.

Inspect hoses that are difficult to see behind other
components.

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6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Inspect all wires in the engine compartment for proper
connections, burned or chafed spots, pinched wires,
contact with sharp edges or contact with hot exhaust
manifolds or pipes.
Basic Knowledge of Tools Required
NOTE: Lack of basic knowledge of this powertrain when
performing diagnostic procedures could result in an
incorrect diagnosis or damage to powertrain
components. Do not attempt to diagnose a powertrain
problem without this basic knowledge.
A basic understanding of hand tools is necessary to effec-
tively use this section of the Service Manual.
Serial Data Communications
Class 2 Serial Data Communications
Government regulations require that all vehicle
manufacturers establish a common communication
system. This vehicle utilizes the ªClass 2º communication
system. Each bit of information can have one of two
lengths: long or short. This allows vehicle wiring to be
reduced by transmitting and receiving multiple signals
over a single wire. The messages carried on Class 2 data
streams are also prioritized. If two messages attempt to
establish communications on the data line at the same
time, only the message with higher priority will continue.
The device with the lower priority message must wait.
The most significant result of this regulation is that it
provides Scan tool manufacturers with the capability to
access data from any make or model vehicle that is sold.
The data displayed on other Scan tools will appear the
same, with some exceptions. Some Scan tools will only
be able to display certain vehicle parameters as values
that are a coded representation of the true or actual value.
On this vehicle the Scan tool displays the actual values for
vehicle parameters. It will not be necessary to perform
any conversions from coded values to actual values.
On-Board Diagnostic (OBD II)
On-Board Diagnostic Tests
A diagnostic test is a series of steps, the result of which is
a pass or fail reported to the diagnostic executive. When
a diagnostic test reports a pass result, the diagnostic
executive records the following data:

The diagnostic test has been completed since the last
ignition cycle.

The diagnostic test has passed during the current
ignition cycle.

The fault identified by the diagnostic test is not
currently active.
When a diagnostic test reports a fail result, the diagnostic
executive records the following data:

The diagnostic test has been completed since the last
ignition cycle.

The fault identified by the diagnostic test is currently
active.

The fault has been active during this ignition cycle.

The operating conditions at the time of the failure.Remember, a fuel trim DTC may be triggered by a list of
vehicle faults. Make use of all information available (other
DTCs stored, rich or lean condition, etc.) when
diagnosing a fuel trim fault.
Comprehensive Component Monitor
Diagnostic Operation
Comprehensive component monitoring diagnostics are
required to monitor emissions-related input and output
powertrain components. The
CARB OBD II
Comprehensive Component Monitoring List Of
Components Intended To illuminate MIL
is a list of
components, features or functions that could fall under
this requirement.
Input Components:
Input components are monitored for circuit continuity and
out-of-range values. This includes rationality checking.
Rationality checking refers to indicating a fault when the
signal from a sensor does not seem reasonable, i.e.
Throttle Position (TP) sensor that indicates high throttle
position at low engine loads or MAP voltage. Input
components may include, but are not limited to the
following sensors:

Vehicle Speed Sensor (VSS)

Crankshaft Position (CKP) sensor

Throttle Position (TP) sensor

Engine Coolant Temperature (ECT) sensor

Manifold Absolute Pressure (MAP) sensor

Mass Air Flow (MAF) sensor
In addition to the circuit continuity and rationality check,
the ECT sensor is monitored for its ability to achieve a
steady state temperature to enable closed loop fuel
control.
Output Components:
Output components are diagnosed for proper response to
control module commands. Components where
functional monitoring is not feasible will be monitored for
circuit continuity and out-of-range values if applicable.
Output components to be monitored include, but are not
limited to, the following circuits:

Control module controlled EVAP Canister Purge
Valve

Electronic Transmission controls

A/C relays

VSS output

MIL control

Cruise control inhibit
Refer to PCM and Sensors in General Descriptions.
Passive and Active Diagnostic Tests
A passive test is a diagnostic test which simply monitors a
vehicle system or component. Conversely, an active test,
actually takes some sort of action when performing
diagnostic functions, often in response to a failed passive
test. For example, the EGR diagnostic active test will
force the EGR valve open during closed throttle decel
and/or force the EGR valve closed during a steady state.
Either action should result in a change in manifold
pressure.

6E±36
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Intrusive Diagnostic Tests
This is any on-board test run by the Diagnostic
Management System which may have an effect on
vehicle performance or emission levels.
Warm-Up Cycle
A warm-up cycle means that engine at temperature must
reach a minimum of 70
C (160
F)
and rise at least 22
C
(40
F) over the course of a trip.
Freeze Frame
Freeze Frame is an element of the Diagnostic
Management System which stores various vehicle
information at the moment an emissions-related fault is
stored in memory and when the MIL is commanded on.
These data can help to identify the cause of a fault. Refer
to
Storing And Erasing Freeze Frame Data in this section
for more detailed information.
Failure Records
Failure Records data is an enhancement of the OBD II
Freeze Frame feature. Failure Records store the same
vehicle information as does Freeze Frame, but it will store
that information for any fault which is stored in on-board
memory, while Freeze Frame stores information only for
emission-related faults that command the MIL on.
System Status and Drive Cycle for
Satisfying Federal Inspection/Maintenance
(I/M 240) Regulations
I/M Ready Status means a signal or flag for each
emission system test that had been set in the PCM. I/M
Ready Status indicates that the vehicle on-board
emissions diagnostics have been run. I/M Ready Status
is not concerned whether the emission system passed or
failed the test, only that on-board diagnosis is complete.
Not all vehicles use all possible I/M flags.
Common OBD II Terms
Diagnostic
When used as a noun, the word diagnostic refers to any
on-board test run by the vehicle's Diagnostic
Management System. A diagnostic is simply a test run on
a system or component to determine if the system or
component is operating according to specification. There
are many diagnostics, shown in the following list:

Misfire

Oxygen sensors

Oxygen sensor heaters

EGR

Catalyst monitoring
Enable Criteria
The term ªenable criteriaº is engineering language for the
conditions necessary for a given diagnostic test to run.
Each diagnostic has a specific list of conditions which
must be met before the diagnostic will run. ªEnable
criteriaº is another way of saying ªconditions requiredº.The enable criteria for each diagnostic is listed on the first
page of the DTC description in Section 6E under the
heading ªConditions for Setting the DTCº. Enable criteria
varies with each diagnostic, and typically includes, but is
not limited to the following items:

engine speed

vehicle speed

ECT

MAF/MAP

barometric pressure

IAT

TP

high canister purge

fuel trim

TCC enabled

A/C on
Trip
Technically, a trip is a key on-run-key off cycle in which all
the enable criteria for a given diagnostic are met, allowing
the diagnostic to run. Unfortunately, this concept is not
quite that simple. A trip is official when all the enable
criteria for a given diagnostic are met. But because the
enable criteria vary from one diagnostic to another, the
definition of trip varies as well. Some diagnostics are run
when the vehicle is at operating temperature, some when
the vehicle first starts up; some require that the vehicle be
cruising at a steady highway speed, some run only when
the vehicle is idle; some diagnostics function with the
TCC disabled. Some run only immediately following a
cold engine start-up.
A trip then, is defined as a key on-run-key off cycle in
which the vehicle was operated in such a way as to satisfy
the enabling criteria for a given diagnostic, and this
diagnostic will consider this cycle to be one trip. However,
another diagnostic with a different set of enable criteria
(which were not met) during this driving event, would not
consider it a trip. No trip will occur for that particular
diagnostic until the vehicle is driven in such a way as to
meet all the enable criteria.
The Diagnostic Executive
The Diagnostic Executive is a unique segment of
software which is designed to coordinate and prioritize
the diagnostic procedures as well as define the protocol
for recording and displaying their results. The main
responsibilities of the Diagnostic Executive are listed as
the following:

Commanding the MIL (ªCheck Engineº lamp) on and
off

DTC logging and clearing

Freeze Frame data for the first emission related DTC
recorded

Non-emission related Service Lamp

Operating conditions Failure Records buffer, (the
number of records will vary)

Current status information on each diagnostic

System Status (I/M ready)

6E±38
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Does not store a Freeze Frame

Stores Fail Record when test fails

Updates the Fail Record each time the diagnostic
test fails

Type D

Non-Emissions related

Not request illumination of any lamp

Stores a History DTC on the
first trip with a fail


Does not store a Freeze Frame

Stores Fail Record when test fails

Updates the Fail Record each time the diagnostic
test fails
IMPORTANT:Only four Fail Records can be stored.
Each Fail Record is for a different DTC. It is possible that
there will not be Fail Records for every DTC if multiple
DTCs are set.
Special Cases of Type B Diagnostic Tests
Unique to the misfire diagnostic, the Diagnostic Executive
has the capability of alerting the vehicle operator to
potentially damaging levels of misfire. If a misfire
condition exists that could potentially damage the
catalytic converter as a result of high misfire levels, the
Diagnostic Executive will command the MIL to ªflashº at a
rate of once per second during those the time that the
catalyst damaging misfire condition is present.
Fuel trim and misfire are special cases of
Type B
diagnostics. Each time a fuel trim or misfire malfunction is
detected, engine load, engine speed, and engine coolant
temperature are recorded.
When the ignition is turned off, the last reported set of
conditions remain stored. During subsequent ignition
cycles, the stored conditions are used as reference for
similar conditions. If a malfunction occurs during two
consecutive trips, the Diagnostic Executive treats the
failure as a normal
Type B diagnostic, and does not use
the stored conditions. However, if a malfunction occurs
on two non-consecutive trips, the stored conditions are
compared with the current conditions. The MIL will then
illuminate under the following conditions:

When the engine load conditions are within 10% of
the previous test that failed.

Engine speed is within 375 rpm, of the previous test
that failed.

Engine coolant temperature is in the same range as
the previous test that failed.Storing and Erasing Freeze Frame Data and Failure
Records
Government regulations require that engine operating
conditions be captured whenever the MIL is illuminated.
The data captured is called Freeze Frame data. The
Freeze Frame data is very similar to a single record of
operating conditions. Whenever the MIL is illuminated,
the corresponding record of operating conditions is
recorded to the Freeze Frame buffer.
Freeze Frame data can only be overwritten with data
associated with a misfire or fuel trim malfunction. Data
from these faults take precedence over data associated
with any other fault. The Freeze Frame data will not be
erased unless the associated history DTC is cleared.
Each time a diagnostic test reports a failure, the current
engine operating conditions are recorded in the
Failure
Records
buffer. A subsequent failure will update the
recorded operating conditions. The following operating
conditions for the diagnostic test which failed
typically
include the following parameters:

Air Fuel Ratio

Air Flow Rate

Fuel Trim

Engine Speed

Engine Load

Engine Coolant Temperature

Vehicle Speed

TP Angle

AP Angle

MAP/BARO

Injector Base Pulse Width

Loop Status
Intermittent Malfunction Indicator Lamp
In the case of an ªintermittentº fault, the MIL (ªCheck
Engineº lamp) may illuminate and then (after three trips)
go ªOFFº. However, the corresponding diagnostic trouble
code will be stored in memory. When unexpected
diagnostic trouble codes appear, check for an intermittent
malfunction.
A diagnostic trouble code may reset. Consult the
ªDiagnostic Aidsº associated with the diagnostic trouble
code. A physical inspection of the applicable sub-system
most often will resolve the problem.
Data Link Connector (DLC)
The provision for communication with the control module
is the Data Link Connector (DLC). It is located at the
lower left of the instrument panel behind a small square
cover. The DLC is used to connect to the Tech 2 Scan
Tool. Some common uses of the Tech 2 are listed below:

6E±57
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Primary System-Based Diagnostic
Primary System-Based Diagnostic
There are primary system-based diagnostics which
evaluate system operation and its effect on vehicle
emissions. The primary system-based diagnostics are
listed below with a brief description of the diagnostic
function:
Oxygen Sensor Diagnosis
The fuel control heated oxygen sensors (Bank 1 HO2S 1
and Bank 2 HO2S 1) are diagnosed for the following
conditions:

Heater performance (time to activity on cold start)

Slow response

Response time (time to switch R/L or L/R)

Inactive signal (output steady at bias voltage ±
approx. 450 mV)

Signal fixed high

Signal fixed low
The catalyst monitor heated oxygen sensors (Bank 1
HO2S 2 and Bank 2 HO2S 2) are diagnosed for the
following conditions:

Heater performance (time to activity on cold start).

Signal fixed low during steady state conditions or
power enrichment (hard acceleration when a rich
mixture should be indicated).

Signal fixed high during steady state conditions or
deceleration mode (deceleration when a lean mixture
should be indicated).

Inactive sensor (output steady at approx. 438 mV).
If the oxygen sensor pigtail wiring, connector or terminal
are damaged, the entire oxygen sensor assembly must
be replaced. DO NOT attempt to repair the wiring,
connector or terminals. In order for the sensor to function
properly, it must have clean reference air provided to it.
This clean air reference is obtained by way of the oxygen
sensor wire(s). Any attempt to repair the wires, connector
or terminals could result in the obstruction of the
reference air and degrade oxygen sensor performance.
Refer to
On-Vehicle Service, Heated Oxygen Sensors in
this section.
Fuel Control Heated Oxygen Sensor
The main function of the fuel control heated oxygen
sensors is to provide the control module with exhaust
stream oxygen content information to allow proper fueling
and maintain emissions within mandated levels. After it
reaches operating temperature, the sensor will generate
a voltage, inversely proportional to the amount of oxygen
present in the exhaust gases. The control module uses
the signal voltage from the fuel control heated oxygen
sensors while in closed loop to adjust fuel injector pulse
width. While in closed loop, the PCM can adjust fuel
delivery to maintain an air/fuel ratio which allows the best
combination of emission control and driveability. The fuel
control heated oxygen sensors are also used to
determine catalyst efficiency.
HO2S Heater
Heated oxygen sensors are used to minimize the amount
of time required for closed loop fuel control to begin
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
Bank2 HO2S 1) to become active. Oxygen sensor
heaters are required by catalyst monitor and sensor
(Bank 1 HO2S 2 and Bank 2 HO2S 2) to maintain a
sufficiently high temperature which allows accurate
exhaust oxygen content readings further away from the
engine.
Catalyst Monitor Heated Oxygen Sensors
and Diagnostic Operation
TS24067
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 PCM has the ability to monitor this process
using the pre-catalyst and post-catalyst heated oxygen
sensors. The pre-catalyst sensor produces an output
signal which indicates the amount of oxygen present in
the exhaust gas entering the three-way catalytic
converter. The post-catalyst 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 pre-catalyst signal will be far
more active than that produced by the post-catalyst
sensor.
In addition to catalyst monitoring, the heated oxygen
sensors have a limited role in controlling fuel delivery. If
the sensor signal indicates a high or low oxygen content
for an extended period of time while in closed loop, the
PCM will adjust the fuel delivery slightly to compensate.

6E±112
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Circuit Description

The powertrain control module (PCM) controls
engine speed by adjusting the position of the throttle
control valve (DC motor). The throttle motor is a DC
motor driven by one coil. The PCM applies current to
the DC motor coil in PWM (%) to adjust the throttle
valve into a passage in the throttle body to allow air
flow. This method allows highly accurate control of
engine speed and quick response to changes in
engine load.

The accelerator position (AP1) sensor circuit
provides a voltage signal relative to accelerator pedal
angle.
The accelerator pedal angle will vary about 13% at
idle position to about 87% at wide open
throttle(WOT).
APS signal is used to determine which DC motor will
adjust throttle position.
After the APS signal has been processed by the
PCM, it will command DC motor to allow movement
of throttle position.
Diagnostic Aids

An intermittent may be caused by a poor connection,
rubbed-through wire insulation or a wire broken inside
the insulation. Check for poor connections or a
damaged harness. Inspect the PCM harness and
connector for improper mating, broken locks,
improperly formed or damaged terminals, poor
terminal-to-wire connection, and damaged harness.

Throttle body ± Check for objects blocking the DC
motor or throttle bore, excessive deposits in the ETC
passage and on the valve spring, and excessive
deposits in the throttle bore and on the throttle valve
plate.

Accelerator pedal ± Check for objects blocking the AP
sensor or pedal arm with spring, and excessive
deposits in the accelerator pedal arm and on the
accelerator pedal.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart:
2. Visually/physically inspect for the following throttle
valve conditions.
3. Visually/physically inspect for the following
accelerator pedal conditions.
5. Check the following circuits for throttle valve and DC
motor. Check the following TP sensor resistance
and DC motor.
7. Check the following circuits for accelerator pedal.
Check the following AP sensor resistance.
10. Following DTC: Software detect Error for ETC
system.
11. Following DTC: Software detect Error for ETC
system.

6E±127
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
PCM Diagnostic Trouble Codes
The following table lists the diagnostic trouble codes
supported by this vehicle application. If any DTCs not
listed here are displayed by a Tech 2, the Tech 2 data may
be faulty; notify the Tech 2 manufacturer of any DTCs
displayed that are not included in the following table.
PCM Diagnostic Trouble Codes
DTC
DescriptionTypeIlluminate
MIL
(Check
Engine
Lamp)Illuminate
RPL
(Reduced
Power
Lamp)
P0101MAF System PerformanceBYe sNo
P0102MAF Sensor Circuit Low FrequencyBYe sNo
P0103MAF Sensor Circuit High FrequencyBYe sNo
P0106MAP Rationality/PerformanceBYe sNo
P0107MAP Circuit Low Input VoltageBYe sNo
P0108MAP Circuit High Input VoltageBYe sNo
P0112IAT Circuit Low Input VoltageBYe sNo
P0113IAT Circuit High Input VoltageBYe sNo
P0117ECT Circuit Low Input VoltageBYe sNo
P0118ECT Circuit High Input VoltageBYe sNo
P0125ECT Insufficient for Closed Loop Fuel ControlBYe sNo
P0128ECT Below Thermostat Regulating TemperatureBYe sNo
P0131O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)BYe sNo
P0132O2 Sensor Circuit High Voltage (Bank 1 Sensor 1)BYe sNo
P0133O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)BYe sNo
P0134O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)BYe sNo
P0135O2 Sensor Heater Circuit (Bank 1 Sensor 1)BYe sNo
P0137O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2)BYe sNo
P0138O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)BYe sNo
P0140O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)BYe sNo
P0141O2 Sensor Heater Circuit (Bank 1 Sensor 2)BYe sNo
P0151O2 Sensor Circuit Low Voltage (Bank 2 Sensor 1)BYe sNo
P0152O2 Sensor Circuit High Voltage (Bank 2 Sensor 1)BYe sNo
P0153O2 Sensor Circuit Slow Response (Bank 2 Sensor 1)BYe sNo
P0154O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 1)BYe sNo
P0155O2 Sensor Heater Circuit (Bank 2 Sensor 1)BYe sNo
P0157O2 Sensor Circuit Low Voltage (Bank 2 Sensor 2)BYe sNo
P0158O2 Sensor Circuit High Voltage (Bank 2 Sensor 2)BYe sNo
P0160O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 2)BYe sNo
P0161O2 Sensor Heater Circuit (Bank 2 Sensor 2)BYe sNo
P0171O2 Sensor ± System too Lean (Bank 1)BYe sNo
P0172O2 Sensor ± System too Rich (Bank 1)BYe sNo
P0174O2 Sensor ± System too Lean (Bank 2)BYe sNo
P0175O2 Sensor ± System too Rich (Bank 2)BYe sNo

6E±140
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0106 MAP System Performance
060R200051
Circuit Description
The manifold absolute pressure (MAP) sensor responds
to changes in intake manifold pressure (vacuum). The
MAP sensor signal voltage to the powertrain control
module (PCM) varies from below 2 volts at idle (high
vacuum) to above 4 volts at wide-open throttle (low
vacuum) at sea level.
The MAP sensor is used to determine manifold pressure
changes while the linear exhaust gas recirculation (EGR)
flow test diagnostic is being run (refer to DTC P0401),
engine vacuum level for some other diagnostics, and
barometric pressure (BARO). The PCM compares the
MAP sensor signal to a calculated MAP based on throttle
position and various engine load factors. If the PCM
detects a MAP signal that varies excessively above or
below the calculated value, DTC P0106 will set.
Conditions for Setting the DTC

No TP sensor DTCs are present.

Engine speed is steady, changing less then 100 RPM.

Engine speed is between 1000 rpm and 4000 rpm.

Throttle position is steady, throttle angle changes less
than 1%.

EGR flow rate is steady, changing less than 4%.

No change in brake switch, A/C clutch, TCC or power
steering pressure switch status.

Above conditions are met for longer than 1 second.

Actual MAP value varies more than 10 kPa.
The MAP value must vary for a total of 10 seconds over
a 20-second period of time that the samples were
monitored.

The failure must occur for 2 consecutive trips.
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 default to a BARO value of 79.3 kPa.

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 P0106 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0106 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.