6E±82
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Tech 2
ParameterRefer To Typical Data
Values
(2500 RPM) Typical Data
Values (IDLE) Units Displayed Data List
Long Term FT
Bank 2 (Long
Term Fuel
Trim)MisfireCounts and
Percentage100 to 150
counts, ±22%
to +17%100 to 150
counts, ±22%
to +17%Diagnosis, Fuel Trim
System Monitor; DTCs:
P0171
MAF (Mass Air
Flow)EngineGrams per
second2.85-6.659.5-16.5General Description and
Operation, MAF; DTCs:
P101, P0102, P0103
MAP kPa
(Manifold
Absolute
EngineKilopascals23-4019-32General Description and
Operation, Manifold
Absolute Pressure (MAP)Absolute
Pressure)Volts0.65-1.320.46-1.10Absolute Pressure (MAP)
Sensor; DTCs: P0106,
P0107, P0108
MILEngineOn/OffOffOffOn-Board Diagnostic
System Check
Misfire Cur. Cyl
#1MisfireCounts0-20-2DTC P0300
Misfire Cur. Cyl
#2MisfireCounts0-20-2DTC P0300
Misfire Cur. Cyl
#3MisfireCounts0-20-2DTC P0300
Misfire Cur. Cyl
#4MisfireCounts0-20-2DTC P0300
Misfire Cur. Cyl
#5MisfireCounts0-20-2DTC P0300
Misfire Cur. Cyl
#6MisfireCounts0-20-2DTC P0300
Misfire Hist.
Cyl #1MisfireCounts00DTC P0300
Misfire Hist.
Cyl #2MisfireCounts00DTC P0300
Misfire Hist.
Cyl #3MisfireCounts00DTC P0300
Misfire Hist.
Cyl #4MisfireCounts00DTC P0300
Misfire Hist.
Cyl #5MisfireCounts00DTC P0300
Misfire Hist.
Cyl #6MisfireCounts00DTC P0300
Misfire Failures
Since First FailMisfireCounts00DTC P0300
Misfire Passes
Since First FailMisfireCounts00DTC P0300
PNP
(Park/Neutral
Position)EngineP-N /
R-D-3-2-LP-NP-N4L30-E Automatic
Transmission Diagnosis
Power
EnrichmentEngineNO/YESNONOGeneral Description and
Operation, Acceleration
Mode
PSP Switch
(Power
Steering
Pressure)EngineNormal/HiNormal
PressureNormal
PressureRefer to 2A Section
6E±103
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Engine Cranks But Will Not Run
StepNo Ye s Value(s) Action
41. Ignition ªOFFº, install a fuel pressure gauge at the
test fitting on the fuel supply line in the engine
compartment. (Use a shop cloth to absorb any fuel
leakage while making the connection.)
2. Ignition ªONº, observe the fuel pressure.
Is the fuel pressure within the specified values, and
does it hold steady?
285 - 375 kPa
(43 ± 55 psi)
Go to Step 6Go to Step 5
5Is any fuel pressure indicated?
Ð
Go to Fuel
System
Electrical TestGo to Fuel
System
Diagnosis
6Install the switch box J 39021±2 at the injector test
connector and activate an injector.
Did the fuel pressure drop when the injector was
activated?
ÐGo to Step 7Go to Step 18
7Install an injector test light at the #2 cylinder injector
harness connector.
Does the light blink when the engine is cranked?
ÐGo to Step 8Go to Step 24
81. Ignition ª OFFº.
2. Disconnect the 11-pin connector at the ION sensing
module.
3. With a test light to B + , probe each of the 6 exposed
ION sensing module pins, one at a time, while the
engine is cranked. (Use the gray narrow Metri - Pak
W flexible female connector from the J - 35616 kit to
make the pin accessible.)
Does the light flash at each pin when the engine is
cranked?
ÐGo to Step 12Go to Step 9
91. Remove the 4-pin connector at the ION sensing
module.
2. Ignition ª ONº.
3. Use a test light at the harness connector to verify
that the module is being supplied with B + and
ground.
Was a problem found?
ÐGo to Step 10Go to Step 11
10Repair the open ignition feed circuit or ground circuit to
the ION sensing module.
Is the action complete?
ÐVerify repairÐ
11Repair the ION sensing module.
Is the action complete?
ÐVerify repairÐ
121. Reconnect the ION sensing module 11-pin
connector.
2. Remove the electrical connector from each coil.
3. With a test light to B+, probe each of the coil
connectors at the wire which runs to the ION
sensing module.
Does the light flash at each coil connector when the
engine is cranked?
ÐGo to Step 14Go to Step 13
13Check for an open circuit between the coil and ION
sensing module.
Is the action complete?
ÐVerify repairÐ
6E±116
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Circuit Description
When the ignition switch is turned ªONº, the powertrain
control module (PCM) will turn ªONº the in-tank fuel
pump. The in-tank fuel pump will remain ªONº as long as
the engine is cranking or running and the PCM is receiving
58X crankshaft position pulses. If there are no 58X
crankshaft position pulses, the PCM will turn the in-tank
fuel pump ªOFFº 2 seconds after the ignition switch is
turned ªONº or 2 seconds after the engine stops running.
The in-tank fuel pump is an electric pump within an
integral reservoir. The in-tank fuel pump supplies fuel
through an in-line fuel filter to the fuel rail assembly. The
fuel pump is designed to provide fuel at a pressure above
the pressure needed by the fuel injectors. A fuel pressure
regulator, attached to the fuel rail, keeps the fuel available
to the fuel injectors at a regulated pressure. Unused fuel
is returned to the fuel tank by a separate fuel return line.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Connect the fuel pressure gauge to the fuel feed line
as shown in the fuel system illustration. Wrap a
shop towel around the fuel pressure connection in
order to absorb any fuel leakage that may occur
when installing the fuel pressure gauge. With the
ignition switch ªONº and the fuel pump running, the
fuel pressure indicated by the fuel pressure gauge
should be 333-376 kPa (48-55 psi). This pressure
is controlled by the amount of pressure the spring
inside the fuel pressure regulator can provide.
3. A fuel system that cannot maintain a constant fuel
pressure has a leak in one or more of the following
areas:
The fuel pump check valve.
The fuel pump flex line.
The valve or valve seat within the fuel pressure
regulator.
The fuel injector(s).
4. Fuel pressure that drops off during acceleration,
cruise, or hard cornering may case a lean condition.
A lean condition can cause a loss of power, surging,
or misfire. A lean condition can be diagnosed using
a Tech 2. If an extremely lean condition occurs, the
oxygen sensor(s) will stop toggling. The oxygen
sensor output voltage(s) will drop below 500 mV.
Also, the fuel injector pulse width will increase.
IMPORTANT:Make sure the fuel system is not
operating in the ªFuel Cut-Off Modeº.
When the engine is at idle, the manifold pressure is
low (high vacuum). This low pressure (high vacuum)
is applied to the fuel pressure regulator diaphragm.
The low pressure (high vacuum) will offset the
pressure being applied to the fuel pressure regulator
diaphragm by the spring inside the fuel pressure
regulator. When this happens, the result is lower fuel
pressure. The fuel pressure at idle will vary slightly as
the barometric pressure changes, but the fuel
pressure at idle should always be less than the fuel
pressure noted in step 2 with the engine ªOFFº.16.Check the spark plug associated with a particular
fuel injector for fouling or saturation in order to
determine if that particular fuel injector is leaking. If
checking the spark plug associated with a particular
fuel injector for fouling or saturation does not
determine that a particular fuel injector is leaking,
use the following procedure:
Remove the fuel rail, but leave the fuel lines and
injectors connected to the fuel rail. Refer to
Fuel Rail
Assembly
in On-Vehicle Service.
Lift the fuel rail just enough to leave the fuel injector
nozzles in the fuel injector ports.
CAUTION: In order to reduce the risk of fire and
personal injury that may result from fuel spraying on
the engine, verify that the fuel rail is positioned over
the fuel injector ports and verify that the fuel injector
retaining clips are intact.
Pressurize the fuel system by connecting a 10 amp
fused jumper between B+ and the fuel pump relay
connector.
Visually and physically inspect the fuel injector
nozzles for leaks.
17.A rich condition may result from the fuel pressure
being above 376 kPa (55 psi). A rich condition may
cause a DTC P0132 or a DTC P0172 to set.
Driveability conditions associated with rich
conditions can include hard starting (followed by
black smoke) and a strong sulfur smell in the
exhaust.
20.This test determines if the high fuel pressure is due
to a restricted fuel return line or if the high fuel
pressure is due to a faulty fuel pressure regulator.
21.A lean condition may result from fuel pressure
below 333 kPa (48 psi). A lean condition may
cause a DTC P0131 or a DTC P0171 to set.
Driveability conditions associated with lean
conditions can include hard starting (when the
engine is cold ), hesitation, poor driveability, lack of
power, surging , and misfiring.
22.Restricting the fuel return line causes the fuel
pressure to rise above the regulated fuel pressure.
Command the fuel pump ªONº with the Tech 2. The
fuel pressure should rise above 376 kPa (55 psi) as
the fuel return line becomes partially closed.
NOTE: Do not allow the fuel pressure to exceed 414 kPa
(60 psi). Fuel pressure in excess of 414 kPa (60 psi) may
damage the fuel pressure regulator.
CAUTION: To reduce the risk of fire and personal
injury:
It is necessary to relieve fuel system pressure
before connecting a fuel pressure gauge. Refer to
Fuel Pressure Relief Procedure, below.
A small amount of fuel may be released when
disconnecting the fuel lines. Cover fuel line
fittings with a shop towel before disconnecting, to
catch any fuel that may leak out. Place the towel in
an approved container when the procedure is
completed.
6E±120
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Exhaust Gas Recirculation (EGR) System Check
060R200050
Circuit Description
A properly operation exhaust gas recirculation (EGR)
system will directly affect the air/fuel requirements of the
engine. Since the exhaust gas introduced into the air/fuel
mixture is an inert gas (contains very little or no oxygen),
less fuel is required to maintain a correct air/fuel ratio.
Introducing exhaust gas into the combustion chamber
lowers combustion temperatures and reduces the
formation of oxides of nitrogen (NOx) in the exhaust gas.
Lower combustion temperatures also prevent detonation.
If the EGR pintle were to stay closed, the inert exhaust
gas would be replaced with air and the air/fuel mixture
would be leaner. The powertrain control module (PCM)
would compensate for the lean condition by adding fuel,
resulting in higher long term fuel trim values.
Diagnostic Aids
The EGR valve chart is a check of the EGR system. An
EGR pintle constantly in the closed position could cause
detonation and high emissions of NOx. It could also result
in high long term fuel trim values in the open throttle cell,
but not in the closed throttle cell. An EGR pintle
constantly in the open position would cause a rough idle.
Also, an EGR mounted incorrectly (rotated 180) could
cause rough idle. Check for the following items:
EGR passages ± Check for restricted or blocked EGR
passages.
Manifold absolute pressure sensor ± A manifold
absolute pressure sensor may shift in calibration
enough to affect fuel delivery. Refer to
Manifold
Absolute Pressure Output Check.
6E±122
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Manifold Absolute Pressure (MAP) Output Check
060R200051
Circuit Description
The manifold absolute pressure (MAP) sensor measures
the changes in the intake MAP which result from engine
load (intake manifold vacuum) and engine speed
changes; and converts these into a voltage output. The
powertrain control module (PCM) sends a 5-volt
reference voltage to the MAP sensor. As the MAP
changes, the output voltage of the sensor also changes.
By monitoring the sensor output voltage, the PCM knows
the MAP. A lower pressure (low voltage) output voltage
will be about 1-2 volts at idle. Higher pressure (high
voltage) output voltage will be about 4-4.8 volts at wide
open throttle. The MAP sensor is also used, under certain
conditions, to measure barometric pressure, allowing the
PCM to make adjustments for different altitudes. The
PCM uses the MAP sensor to diagnose proper operation
of the EGR system, in addition to other functions.
Test Description
IMPORTANT:Be sure to used the same diagnostic test
equipment for all measurements.
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Applying 34 kPa (10 inch Hg) vacuum to the MAP
sensor should cause the voltage to be 1.5-2.1 volts
less than the voltage at step 1. Upon applying
vacuum to the sensor, the change in voltage should
be instantaneous. A slow voltage change indicates
a faulty sensor.
3. Check the vacuum hose to the sensor for leaking or
restriction, Be sure that no other vacuum devices
are connected to the MAP hose.
IMPORTANT:Make sure the electrical connector
remains securely fastened.
4. Disconnect the sensor from the bracket. Twist the
sensor with your hand to check for an intermittent
connection. Output changes greater than 0.10 volt
indicate a bad sensor.
6E±123
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Manifold Absolute Pressure (MAP) Output Check
StepActionValue(s)Ye sNo
11. Turn the ignition ªOFFº and leave it ªOFFº for 15
seconds.
2. Ignition ªONº. Don't crank engine.
3. The Tech 2 should indicate a manifold absolute
pressure (MAP) sensor voltage.
4. Compare this scan reading to scan reading of a
known good vehicle obtained using the exact same
procedure as in Steps 1-4.
Is the voltage reading the same +/±0.40 volt?
ÐGo to Step 2Go to Step 5
21. Disconnect the vacuum hose at the MAP sensor
and plug the hose.
2. Connect a hand vacuum pump to the MAP sensor.
3. Start the engine.
4. Apply 34 kPa (10 in.Hg) of vacuum and note the
voltage change.
Is the voltage change 1.5-2.1 volts less than Step 1?
ÐGo to Step 3Go to Step 4
3Check the sensor cover for leakage or restriction.
Does the hose supply vacuum to the MAP sensor only?
ÐGo to Step 5Go to Step 4
4Repair the hose blockage.
Is the action complete?
ÐVerify repairÐ
5Check the sensor connection.
Is the sensor connection good?
ÐGo to Step 6Go to Step 7
6Refer to On-Vehicle Service, MAP Sensor.
Is the action complete?ÐVerify repairÐ
7Repair the poor connection.
Is the action complete?
ÐVerify repairÐ
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.
6E±143
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0107 MAP Sensor Circuit Low Voltage
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 with the ignition ªONº, engine
not running or at wide-open throttle (low vacuum).
The MAP sensor is used to determine manifold pressure
changes while the exhaust gas recirculation (EGR) flow
test diagnostic is being run (refer to
DTC P0401), to
determine engine vacuum level for some other
diagnostics and to determine barometric pressure
(BARO). The PCM monitors the MAP signals for voltages
outside the normal range of the MAP sensor. If the PCM
detects a MAP signal voltage that is excessively low, DTC
P0107 will be set.
Conditions for Setting the DTC
No TP sensor DTCs present.
Engine is running.
Throttle angle is above 1% if engine speed is less than
1000 RPM.
Throttle angle is above 2% if engine speed is above
1000 RPM.
The MAP sensor indicates manifold absolute pressure
at or below 11 kPa for a total of approximately 10
seconds over a 16-second period.
Ignition voltage more than 11 volts.
Action Taken When the DTC Sets
The PCM will ON the MIL after second trip with
detected fault.
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 P0107 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
DTC P0107 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:
Check for intermittent codes.
The MAP sensor shares a 5 Volt reference with the
Fuel Tank Pressure Sensor. If these codes are also
set, it could indicate a problem with the 5 Volt reference
circuit .
The MAP sensor shares a ground with the Fuel Tank
Pressure Sensor, the ECT sensor, and the
Transmission Fluid Temperature sensor.
Poor connection at PCM ± Inspect harness connectors
for backed-out terminals, improper mating, broken