6E±113
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Electric Throttle Control (ETC) System Check
StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Visually/physically inspect for the following conditions:
Throttle body tampering.
Restricted intake throttle system. Check for a
possible collapsed air intake duct, restricted air
filter element, or foreign objects blocking the air
intake system.
Throttle body: Check for objects blocking the
throttle passage or throttle bore, excessive
deposits in the throttle passage and on the throttle
valve, and excessive deposits in the throttle bore
and on the throttle plate.
Throttle body with lever: When check for objects
to send round the throttle spring lever that lever is
smooth movement by less than 9 l´bm{1.0 N´m},
and spring lever has not excessive play.
Throttle function: Check for the throttle function.
When ignition switch ªONº that throttle lever is
smooth operated by step on the accelerator
pedal.
Did any of the above require a repair?
Ð
Refer to
appropriate
section for
on-vehicle
service
Go to Step 3
3Visually/physically inspect for the following conditions:
Accelerator pedal tampering.
Accelerator pedal : Check for objects blocking the
spring or pedal arm.
Accelerator pedal : For check for objects to move
the accelerator pedal that pedal is smooth
movement, and accelerator pedal arm has not
excessive play.
Did any of the above require a repair?
Ð
Refer to
appropriate
section for
on-vehicle
service
Go to Step 4
41. Check for a poor connection at the throttle body
harness connector.
2. Check for a poor connection at the accelerator
position sensor harness connector.
3. If a problem is found, replace faulty terminals as
necessary.
Was a problem found?
ÐVerify repairGo to Step 5
5Check the following circuits for an open, short to
voltage, short to ground, or poor connection at the
PCM:
Throttle position sensor 1 circuit.
Throttle position sensor 2 circuit.
Throttle DC motor circuit.
Throttle position sensor resistance.
Throttle DC motor resistance.
If a problem is found, repair as necessary.
Was a problem found?
Vcc±GND
1±7k
SIG±GND
change
resistance
0.3±100
Verify repairGo to Step 6
6E±117
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Fuel Pressure Relief Procedure
1. Remove the fuel cap.
2. Remove the fuel pump relay from the underhood
relay center.
3. Start the engine and allow it to stall.
4. Crank the engine for an additional 3 seconds.
Fuel Gauge Installation
1. Remove the shoulder fitting cap.
2. Install fuel gauge J 34730-1 to the fuel feed line
located in front of and above the right side valve train
cover.
3. Reinstall the fuel pump relay.
Fuel System Diagnosis
StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Turn the ignition ªOFFº.
2. Turn the air conditioning system ªOFFº.
3. Relieve fuel system pressure and install the fuel
pressure gauge.
4. Turn the ignition ªONº.
NOTE: The fuel pump will run for approximately 2
seconds. Use the Tech 2 to command the fuel pump
ªONº.
(Refer to the Miscellaneous Test.)
5. Observe the fuel pressure indicated by the fuel
pressure gauge with the fuel pump running.
Is the fuel pressure within the specified limits?
290-376 kPa
(42-55 psi)
Go to Step 3Go to Step 17
3NOTE: The fuel pressure will drop when the fuel pump
stops running, then it should stabilize and remain
constant.
Does the fuel pressure indicated by the fuel pressure
gauge remain constant?
ÐGo to Step 4Go to Step 12
41. When the vehicle is at normal operation
temperature, turn the ignition ªONº to build fuel
pressure and observe the measurement on the
gauge.
2. Start the engine and observe the fuel pressure
gauge.
Did the reading drop by the amount specified after the
engine was started?
21-105 kPa
(3-15 psi)
Go to Step 5Go to Step 9
5Is fuel pressure dropping off during acceleration,
cruise, or hard cornering?
ÐGo to Step 6
Check for
improper fuel
6Visually and physically inspect the following items for a
restriction:
The in-pipe fuel filter.
The fuel feed line.
Was a restriction found?
ÐVerify repairGo to Step 7
7Remove the fuel tank and visually and physically
inspect the following items:
The fuel pump strainer for a restriction.
The fuel line for a leak.
Verify that the correct fuel pump is in the vehicle.
Was a problem found in any of these areas?
ÐVerify repairGo to Step 8
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±131
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0101 MAF System Performance
060R200052
Circuit Description
The mass air flow (MAF) sensor measures the amount of
air which passes through it into the engine during a given
time. The powertrain control module (PCM) uses the
mass air flow information to monitor engine operating
conditions for fuel delivery calculations. A large quantity
of air entering the engine indicates an acceleration or high
load situation, while a small quantity or air indicates
deceleration or idle.
The MAF sensor produces a frequency signal which can
be monitored using a Tech 2. The frequency will vary
within a range of around 4 to 7g/s at idle to around 25 to
40g/s at maximum engine load. DTC P0101 will be set if
the signal from the MAF sensor does not match a
predicted value based on throttle position and engine
RPM.
Conditions for setting the DTC
The engine is running.
No TP sensor and MAP sensor DTCs are set.
No MAF frequency DTCs are set.
System voltage is between 11.5 volts and 16 volts.
Action Taken When the DTC Sets
The PCM will ON the MIL after second trip with
detected fault.
The PCM calculates an air flow value based on idle air
control valve position, throttle position, RPM and
barometric pressure.The PCM will store condition 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 P0101 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.
DTC P0101 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.
The duct work at the MAF sensor for leaks.
An engine vacuum leak.
The PCV system for vacuum leaks.
An incorrect PCV valve.
The engine oil dip stick not fully seated.
The engine oil fill cap loose or missing.
Check for the following conditions:
6E±132
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
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
Mass Air Flow (MAF) display on the Tech 2 while
moving connectors and wiring harnesses related to the
sensor.
Plugged intake air duct or filter element
A wide±open throttle acceleration from a stop should
cause the mass air flow displayed on a Tech 2 toincrease from about 3±6 g/s at idle to 100 g/s or greater
at the time of the 1±2 shift. If not, check for a restriction.
A change in the display will indicate the location of
the fault.
If DTC P0101 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 P001 Diagnostic Chart may
isolate the cause of the fault.
DTC P0101 ± MAF System Performance
StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªOFFº.
2. Disconnect the Mass Air Flow (MAF) Sensor
harness connector from the MAF Sensor.
3. Place an unpowered test lamp between the 12 volt
signal circuit and the ground circuit, both at the MAF
Sensor connector.
4. Ignition ªONº, EngineªOFFº.
Did the test lamp illuminate?
ÐGo to Step 6Go to Step 3
31. Ignition ªONº, Engine ªOFFº.
2. Using a Digital Voltmeter (DVM), check the 12 volt
signal circuit for the correct voltage.
Did the DVM indicate a value within the following
range?
11.5 to 12.5
Volt
Go to Step 5Go to Step 4
41. Ignition ªOFFº.
2. Check the 12 volt signal circuit for the following
conditions:
An open circuit
A short to ground
Was the problem found?
ÐVerify repairÐ
5Check the MAF ground circuit for the following
conditions:
An open circuit
A short to voltage
Was a problem found?
ÐVerify repairÐ
61. Ignition ªOFFº.
2. Check the MAF Sensor signal circuit between the
PCM and the MAF Sensor for the following
conditions:
An open circuit
A short to ground
A short to battery voltage
Was a problem found?
ÐVerify repairGo to Step 7
6E±134
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0102 MAF Sensor Circuit Low Frequency
060R200052
Circuit Description
The mass air flow (MAF) sensor measures the amount of
air which passes through it into the engine during a given
time. The powertrain control module (PCM) uses the
mass air flow information to monitor engine operating
conditions for fuel delivery calculations. A large quantity
of air entering the engine indicates an acceleration or high
load situation, while a small quantity of air indicates
deceleration or idle.
The MAF sensor produces a frequency signal which can
be monitored using a Tech 2. The frequency will vary
within a range of around 4 to 7g/s at idle to around 25 to 40
g/s at maximum engine load. DTC P0102 will be set if the
signal from the MAF sensor is below the possible range of
a normally operating MAF sensor.
Conditions for Setting the DTC
The engine is running above 500 RPM for more than
10 seconds.
System voltage is above 11.5 volts.
MAF signal frequency is below 1.6g/s for a total of
50-percent of the last 1000 samples monitored. A
sample is taken every cylinder event.
Action Taken When the DTC Sets
The PCM will ON the MIL after second trip with
detected fault.
The PCM calculates an air flow value based on idle air
control valve position, throttle position, RPM and
barometric pressure.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 P0102 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
DTC P0102 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.
Misrouted harness ± Inspect the MAF sensor harness
to ensure that it is not routed too close to high voltage
wires.
Damaged harness ± Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
Tech 2 while moving connectors and wiring harnesses
related to the MAF sensor. A change in the display will
indicate the location of the fault.
Plugged intake air duct or filter element ± A wide-open
throttle acceleration from a stop should cause the
mass air flow displayed on a Tech 2 to increase from
6E±135
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
about 3-6 g/second at idle to 100 g/second or greater
at the time of the 1-2 shift. If not, check for a restriction.
If DTC P0102 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.2. This step verifies that the problem is present at idle.
4. A voltage reading of less than 4 or over 5 volts at the
MAF sensor signal circuit indicates a fault in the
wiring or a poor connection.
5. This verifies that ignition feed voltage and a good
ground are available at the MAF sensor.
DTC P0102 ± MAF Sensor Circuit Low Frequency
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.
2. With the engine idling, monitor ªMAF Frequencyº
display on the Tech 2.
Is the ªMAF Frequencyº below the specified value?
1.6 g/sGo to Step 3Go to Step 5
31. Ignition ªONº, engine ªOFFº.
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records
conditions as noted.
4. Using a Tech 2, monitor ªDTCº info for DTC P0102.
Does the Tech 2 indicate DTC P0102 failed this
ignition?
ÐGo to Step 4
Refer to
Diagnostic
Aids
41. Ignition ªOFFº.
2. Disconnect the MAF sensor connector.
3. Ignition ªONº, engine ªOFFº.
4. Using a DVM, measure voltage between the MAF
sensor signal circuit and battery ground.
Is the voltage near the specified value?
11.5±12 VGo to Step 5Go to Step 8
5Connect a test light between the MAF sensor ignition
feed and ground circuits at the MAF sensor harness
connector.
Is the test light ªONº?
ÐGo to Step 7Go to Step 6
6Connect a test light between the MAF sensor ignition
feed circuit and battery ground.
Is the test light ªONº?
ÐGo to Step 11Go to Step 7
71. Check for a poor connection at the MAF sensor.
2. If a poor connection is found, replace the faulty
terminal(s).
Was a poor connection found?
ÐVerify repairGo to Step 12
81. Ignition ªOFFº.
2. Disconnect the MAF sensor.
3. Disconnect the PCM connector for the MAF signal
circuit.
4. Ignition ªONº, engine ªOFFº.
5. With the DVM, measure the voltage between the
MAF signal terminal at the PCM and battery ground.
Is the voltage under the specified value?
0 VGo to Step 9Go to Step 10
6E±137
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0103 MAF Sensor Circuit High Frequency
060R200052
Circuit Description
The mass air flow (MAF) sensor measures the amount of
air which passes through it into the engine during a given
time. The powertrain control module (PCM) uses the
mass air flow information to monitor engine operating
conditions for fuel delivery calculations. A large quantity
of air entering the engine indicates an acceleration or high
load situation, while a small quantity of air indicates
deceleration or idle.
The MAF sensor produces a frequency signal which can
be monitored using a Tech 2. The frequency will vary
within a range of around 4 to 7g/s at idle to around 25 to 40
g/s at maximum engine load. DTC P0103 will be set if the
signal from the MAF sensor is above the possible range of
a normally operating MAF sensor.
Conditions for Setting the DTC
The engine is running above 500 RPM for more than
10 seconds.
System voltage is above 11.5 volts.
MAF signal frequency is above 40g/s for a total of 50
percent of the last 200 samples monitored. A sample
is taken every cylinder event.
Action Taken When the DTC Sets
The PCM will ON the MIL after second trip with
detected the fault.The PCM calculates an airflow value based on idle air
control valve position, throttle position, RPM and
barometric pressure.
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 P0103 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
DTC P0103 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
If DTC P0103 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. This step verifies that the problem is present at idle.