6E±562
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
EVAP Canister
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the two hoses from the EVAP canister.
3. Disconnect the fuel vapor connector and the purge
hose from the EVAP canister vent solenoid.
4. Remove the two retaining bolts the EVAP canister to
the mounting bracket on the cross member.
5. Remove the retaining bolt on the mounting bracket
the slide the canister out of mounting bracket.
060R200081
Inspection Procedure
1. Inspect the hoses for cracks and leaks.
2. Inspect the canister for a damaged case.
Installation Procedure
1. Slide the canister into mounting bracket and install
the mounting bracket bolt.
2. Install the retaining bolts the EVAP canister to the
mounting bracket on the cross member.
3. Connect the fuel vapor connector to the EVAP
canister vent solenoid.4. Connect the two hoses to the EVAP canister.
060R200081
5. Disconnect the negative battery cable.
EVAP Canister Vent Solenoid
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the connector and hose.
014RW132
6E±563
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
3. Slide the out of EVAP canister vent solenoid from
mounting bracket.
014RW135
Inspection Procedure
1. Check for cracks or leaks.
2. Energize the solenoid and try to blow through it. The
solenoid should not allow passage of air when
energized. (J 35616 Connector Test Kit can be used
to easily attach jumper wires from the battery to the
solenoid).
Installation Procedure
1. Slide the into EVAP canister vent solenoid into the
mounting bracket.
014RW135
2. Connect the connector and hose.
014RW132
3. Connect the negative battery cable.
Fuel Tank Pressure
(Vapor Pressure) Sensor
Removal Procedure
1. Remove the fuel pump assembly. Refer to Fuel Tank
In Fuel Pump
.
2. Carefully pry the fuel tank pressure sensor out of the
top of the fuel pump assembly.
014RW133
Inspection Procedure
1. Inspect the vapor pressure sensor for cracks in the
housing and corrosion on the electrical terminals.
2. Inspect the rubber grommet for tears and signs of rot.
6E±564
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Installation Procedure
1. Install the rubber grommet on the fuel pump
assembly.
014RW133
2. Install the fuel tank vapor pressure sensor on the fuel
pump assembly.
Insert the sensor nipple firmly into the grommet.
Keep twisting and pushing the sensor until the wide
portion of the nipple shows on the other side of the
grommet.
3. Install the fuel pump assembly on the fuel tank. Refer
to
Fuel Tank In Fuel Pump..
EVAP Canister Purge Solenoid
(Purge Duty Solenoid Valve)
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the electrical connector from the EVAP
canister purge solenoid.3. Disconnect the vacuum hoses from the EVAP
canister purge solenoid.
060R200080
4. Remove the EVAP canister purge solenoid retaining
bolt from the common chamber.
5. Remove the EVAP canister purge solenoid.
Installation Procedure
1. Install the EVAP canister purge solenoid on the upper
intake manifold.
2. Install the EVAP canister purge solenoid retaining
bolt.
Tighten
Tighten the bolts to 20 N´m (16 lb ft.).
3. Connect the vacuum hoses to the EVAP canister
purge solenoid.
4. Connect the electrical connector to the EVAP canister
purge solenoid.
060R200080
6E±565
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Fuel Tank Vent Valve
(Vent Solenoid Valve)
Removal and Installation Procedure
Refer to Fuel Pump section.
Linear Exhaust Gas
Recirculation (EGR) Valve
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the electrical connector at the EGR valve.
014RW139
3. Remove the bolts from the common chamber.
014RW098
4. Remove the EGR valve from the common chamber
manifold.
5. Remove the gasket from the common chamber
manifold.
Installation Procedure
1. Install the gasket on the common chamber.
2. Install the EGR valve on the common chamber.
3. Secure the EGR valve and the gasket with the bolts.
Torque: 25 N´m (18 Ib ft)
NOTE: It is possible to install the EGR valve rotated 180
from the correct position. Make sure that the base of the
valve is placed so that it aligns with the mounting flange.
014RW098
4. Connect the electrical connector at the EGR valve.
014RW139
5. Connect the negative battery cable.
6E±575
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Powertrain Control Module (PCM)
The powertrain control module (PCM) is located in the
passenger compartment below the center console. The
PCM controls the following:
Fuel metering system.
Transmission shifting (automatic transmission only).
Ignition timing.
On-board diagnostics for powertrain functions.
The PCM constantly observes the information from
various sensors. The PCM controls the systems that
affect vehicle performance. The PCM performs the
diagnostic function of the system. It can recognize
operational problems, alert the driver through the MIL
(Check Engine lamp), and store diagnostic trouble codes
(DTCs). DTCs identify the problem areas to aid the
technician in making repairs.
PCM Function
The PCM supplies either 5 or 12 volts to power various
sensors or switches. The power is supplied through
resistances in the PCM which are so high in value that a
test light will not light when connected to the circuit. In
some cases, even an ordinary shop voltmeter will not give
an accurate reading because its resistance is too low.
Therefore, a digital voltmeter with at least 10 megohms
input impedance is required to ensure accurate voltage
readings. Tool J 39200 meets this requirement. The PCM
controls output circuits such as the injectors, fan relays,
etc., by controlling the ground or the power feed circuit
through transistors or through either of the following two
devices:
Output Driver Module (ODM)
Quad Driver Module (QDM)
060RY00068
PCM Components
The PCM is designed to maintain exhaust emission levels
to government mandated standards while providing
excellent driveability and fuel efficiency. The PCM
monitors numerous engine and vehicle functions via
electronic sensors such as the throttle position (TP)sensor, heated oxygen sensor (HO2S), and vehicle
speed sensor (VSS). The PCM also controls certain
engine operations through the following:
Fuel injector control
Ignition control module
ION sensing module
Automatic transmission shift functions
Cruise control
Evaporative emission (EVAP) purge
A/C clutch control
PCM Voltage Description
The PCM supplies a buffered voltage to various switches
and sensors. It can do this because resistance in the
PCM is so high in value that a test light may not illuminate
when connected to the circuit. An ordinary shop
voltmeter may not give an accurate reading because the
voltmeter input impedance is too low. Use a 10-megohm
input impedance digital voltmeter (such as J 39200) to
assure accurate voltage readings.
The input/output devices in the PCM include
analog-to-digital converters, signal buffers, counters,
and special drivers. The PCM controls most components
with electronic switches which complete a ground circuit
when turned ªON.º These switches are arranged in
groups of 4 and 7, called either a surface-mounted quad
driver module (QDM), which can independently control up
to 4 output terminals, or QDMs which can independently
control up to 7 outputs. Not all outputs are always used.
PCM Input/Outputs
Inputs ± Operating Conditions Read
Air Conditioning ªONº or ªOFFº
Engine Coolant Temperature
Crankshaft Position
Exhaust Oxygen Content
Electronic Ignition
Manifold Absolute Pressure
Battery Voltage
Throttle Position
Vehicle Speed
Fuel Pump Voltage
Power Steering Pressure
Intake Air Temperature
Mass Air Flow
Engine Knock
Acceleration Position
Outputs ± Systems Controlled
EVAP Canister Purge
Exhaust Gas Recirculation (EGR)
Ignition Control
Fuel Control
ION Sensing Module
Electric Fuel Pump
Air Conditioning
6E±577
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Aftermarket Electrical and Vacuum
Equipment
Aftermarket (add-on) electrical and vacuum equipment is
defined as any equipment which connects to the vehicle's
electrical or vacuum systems that is installed on a vehicle
after it leaves the factory. No allowances have been
made in the vehicle design for this type of equipment.
NOTE: No add-on vacuum equipment should be added
to this vehicle.
NOTE: A d d - o n e l e c t r i c a l equipment must only be
connected to the vehicle's electrical system at the battery
(power and ground).
Add-on electrical equipment, even when installed to
these guidelines, may still cause the powertrain system to
malfunction. This may also include equipment not
connected to the vehicle electrical system such as
portable telephones and radios. Therefore, the first step
in diagnosing any powertrain problem is to eliminate all
aftermarket electrical equipment from the vehicle. After
this is done, if the problem still exists, it may be diagnosed
in the normal manner.
Electrostatic Discharge Damage
Electronic components used in the PCM are often
designed to carry very low voltage. Electronic
components are susceptible to damage caused by
electrostatic discharge. Less than 100 volts of static
electricity can cause damage to some electronic
components. By comparison, it takes as much as 4000
volts for a person to feel even the zap of a static
discharge.
TS23793There are several ways for a person to become statically
charged. The most common methods of charging are by
friction and induction.
An example of charging by friction is a person sliding
across a vehicle seat.Charge by induction occurs when a person with well
insulated shoes stands near a highly charged object
and momentary touches ground. Charges of the
same polarity are drained off leaving the person
highly charged with the opposite polarity. Static
charges can cause damage, therefore it is important
to use care when handling and testing electronic
components.
NOTE: To p r e ve n t p ossible electrostatic discharge
damage, follow these guidelines:
Do not touch the PCM connector pins or soldered
components on the PCM circuit board.
Do not open the replacement part package until the
part is ready to be installed.
Before removing the part from the package, ground
the package to a known good ground on the vehicle.
If the part has been handled while sliding across the
seat, while sitting down from a standing position, or
while walking a distance, touch a known good ground
before installing the part.
General Description (Air Induction)
Air Induction System
The air induction system filters contaminants from the
outside air, and directs the progress of the air as it is
drawn into the engine. A remote-mounted air cleaner
prevents dirt and debris in the air from entering the
engine. The air duct assembly routes filtered air to the
throttle body. Air enters the engine by to following steps:
1. Through the throttle body.
2. Into the common chamber.
3. Through the cylinder head intake ports.
4. Into the cylinders.
055RV010
6E±578
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
General Description (Fuel Metering)
Acceleration Mode
The PCM provides extra fuel when it detects a rapid
increase in the throttle position and the air flow.
Battery Voltage Correction Mode
When battery voltage is low, the PCM will compensate for
the weak spark by increasing the following:
The amount of fuel delivered.
The idle RPM.
Ignition dwell time.
Clear Flood Mode
Clear a flooded engine by pushing the accelerator pedal
down all the way. The PCM then de-energizes the fuel
injectors. The PCM holds the fuel injectors de-energized
as long as the throttle remains above 80% and the engine
speed is below 800 RPM. If the throttle position becomes
less than 80%, the PCM again begins to pulse the
injectors ªONº and ªOFF,º allowing fuel into the cylinders.
Deceleration Mode
The PCM reduces the amount of fuel injected when it
detects a decrease in the throttle position and the air flow.
When deceleration is very fast, the PCM may cut off fuel
completely for short periods.
Engine Speed/Vehicle Speed/Fuel Disable
Mode
The PCM monitors engine speed. It turns off the fuel
injectors when the engine speed increases above 6400
RPM. The fuel injectors are turned back on when engine
speed decreases below 6150 RPM.
Fuel Cutoff Mode
No fuel is delivered by the fuel injectors when the ignition
is ªOFF.º This prevents engine run-on. In addition, the
PCM suspends fuel delivery if no reference pulses are
detected (engine not running) to prevent engine flooding.
Fuel Injector
The sequential multiport fuel injection (SFI) fuel injector is
a solenoid-operated device controlled by the PCM. The
PCM energizes the solenoid, which opens a valve to allow
fuel delivery.
The fuel is injected under pressure in a conical spray
pattern at the opening of the intake valve. Excess fuel not
used by the injectors passes through the fuel pressure
regulator before being returned to the fuel tank.
A fuel injector which is stuck partly open will cause a loss
of fuel pressure after engine shut down, causing long
crank times.
014RY00009
Fuel Metering System Components
The fuel metering system is made up of the following
parts:
The fuel injectors.
The throttle body.
The fuel rail.
The fuel pressure regulator.
The PCM.
The crankshaft position (CKP) sensor.
The ION sensing module.
The fuel pump.
The fuel pump relay.
Basic System Operation
The fuel metering system starts with the fuel in the fuel
tank. An electric fuel pump, located in the fuel tank,
pumps fuel to the fuel rail through an in-line fuel filter. The
pump is designed to provide fuel at a pressure above the
pressure needed by the injectors. A fuel pressure
regulator in the fuel rail keeps fuel available to the fuel
injectors at a constant pressure. A return line delivers
unused fuel back to the fuel tank. Refer to
Section 6C for
further information on the fuel tank, line filter, and fuel
pipes.
Fuel Metering System Purpose
The basic function of the air/fuel metering system is to
control the air/fuel delivery to the engine. Fuel is delivered
to the engine by individual fuel injectors mounted in the
intake manifold near each intake valve.
The main control sensor is the heated oxygen sensor
(HO2S) located in the exhaust system. The HO2S tells
the PCM how much oxygen is in the exhaust gas. The
PCM changes the air/fuel ratio to the engine by controlling
the amount of time that fuel injector is ªON.º The best
mixture to minimize exhaust emissions is 14.7 parts of air
to 1 part of gasoline by weight, which allows the catalytic
converter to operate most efficiently. Because of the
constant measuring and adjusting of the air/fuel ratio, the
fuel injection system is called a ªclosed loopº system.
6E±583
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
between the seats. In extreme cases, exhaust blow-by
and damage beyond simple gap wear may occur.
Cracked or broken insulators may be the result of
improper installation, damage during spark plug
re-gapping, or heat shock to the insulator material. Upper
insulators can be broken when a poorly fitting tool is used
during installation or removal, when the spark plug is hit
from the outside, or is dropped on a hard surface. Cracks
in the upper insulator may be inside the shell and not
visible. Also, the breakage may not cause problems until
oil or moisture penetrates the crack later.
TS23994
A/C Clutch Diagnosis
A/C Clutch Circuit Operation
A 12-volt signal is supplied to the A/C request input of the
PCM when the A/C is selected through the A/C control
switch.
The A/C compressor clutch relay is controlled through the
PCM. This allows the PCM to modify the idle air control
position prior to the A/C clutch engagement for better idle
quality. If the engine operating conditions are within their
specified calibrated acceptable ranges, the PCM will
enable the A/C compressor relay. This is done by
providing a ground path for the A/C relay coil within the
PCM. When the A/C compressor relay is enabled,
battery voltage is supplied to the compressor clutch coil.
The PCM will enable the A/C compressor clutch
whenever the engine is running and the A/C has been
requested. The PCM will not enable the A/C compressor
clutch if any of the following conditions are met:
The throttle is greater than 90%.
The engine speed is greater than 6315 RPM.
The ECT is greater than 119C (246F).
The IAT is less than 5C (41F).
The throttle is more than 80% open.
A/C Clutch Circuit Purpose
The A/C compressor operation is controlled by the
powertrain control module (PCM) for the following
reasons:
It improvises idle quality during compressor clutch
engagement.
It improvises wide open throttle (WOT) performance.
It provides A/C compressor protection from operation
with incorrect refrigerant pressures.
The A/C electrical system consists of the following
components:
The A/C control head.
The A/C refrigerant pressure switches.
The A/C compressor clutch.
The A/C compressor clutch relay.
The PCM.
A/C Request Signal
This signal tells the PCM when the A/C mode is selected
at the A/C control head. The PCM uses this to adjust the
idle speed before turning on the A/C clutch. The A/C
compressor will be inoperative if this signal is not
available to the PCM.
Refer to
A/C Clutch Circuit Diagnosis section for A/C
wiring diagrams and diagnosis for A/C electrical system.
General Description (Evaporative
(EVAP) Emission System)
EVAP Emission Control System Purpose
The basic evaporative emission (EVAP) control system
used on all vehicles is the charcoal canister storage
method. Gasoline vapors from the fuel tank flow into the
canister through the inlet labeled ªTANK.º These vapors
are absorbed into the activated carbon (charcoal) storage
device (canister) in order to hold the vapors when the
vehicle is not operating. The canister is purged by PCM
control when the engine coolant temperature is over 60C
(140F), the IAT reading is over 10C (50F), and the
engine has been running. Air is drawn into the canister
through the air inlet grid. The air mixes with the vapor and
the mixture is drawn into the intake manifold.
EVAP Emission Control System Operation
The EVAP canister purge is controlled by a solenoid valve
that allows the manifold vacuum to purge the canister.
The powertrain control module (PCM) supplies a ground
to energize the solenoid valve (purge on). The EVAP
purge solenoid control is pulse-width modulated (PWM)
(turned on and off several times a second). The duty
cycle (pulse width) is determined by engine operating
conditions including load, throttle positron, coolant
temperature and ambient temperature. The duty cycle is
calculated by the PCM. The output is commanded when
the appropriate conditions have been met. These
conditions are:
The engine is fully warmed up.
The engine has been running for a specified time.
The IAT reading is above 10C (50F).