6E±468
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1326 ION Sensing Module Combustion Quality Input Circuit Fault
060R200068
Circuit Description
The Power Control Module (PCM) checks the validity of
the signals used in the ION Sensing module at the
following engine operating conditions.
The test is performed to evacuate the Combustion
Quality (CQ) signal pulse width if it is within a
predetermined range. If the CQ signal pulse width is
out of the predetermined range, the fail counter will be
incremented. If the failure counter exceeds the
calibration, then test is complete and a failure will be
reported. If the sample counter threshold is reached
before the failure threshold, then the test is complete
and a pass will be reported. This test will detect an
open/short in the CQ line circuit, ION Sensing module
faults and analog input faults in the PCM.
Conditions for setting the DTC
Ignition voltage is between 10volt and 16 volts.
No Crank DTCs set.
No cylinder ID DTCs set.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
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 P1326 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.
DTC P1326 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.
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.
Damaged harness-Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
moving connectors and wiring harnesses related to the
sensor.
A change in the display will indicate the location of
the fault. If DTC P1326 cannot be duplicated, the
information included in the Failure Records data can
6E±477
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1441 EVAP System Flow During Non-Purge
060RY00398
Circuit Description
Canister purge is controlled by a solenoid valve that
allows manifold vacuum to purge the canister. The
powertrain control module (PCM) supplies a ground to
energize the solenoid valve (purge ªONº). The EVAP
purge solenoid control is pulse-width modulated (PWM)
or turned ªONº and ªOFFº several times a second. The
duty cycle (pulse width) is determined by engine
operating conditions including load, throttle position,
coolant temperature and ambient temperature. The duty
cycle is calculated by the PCM and the output is
commanded when the appropriate conditions have been
met.
Conditions for Setting the DTC
No active ECT sensor, IAT sensor, MAP sensor, or TP
sensor DTCs set.
BARO reading is above 85 kPa.
Engine coolant temperature is below 70C (158F).
Start-up intake air temperature (IAT) and start-up
engine coolant temperature (ECT) are both above 5C
(41F).
The difference between start-up ECT and start-up IAT
is less than 25C (45F).
TP sensor indicates a throttle position above 12%.
Battery voltage is between 11.5 volts and 16 volts.
Engine speed is between 800 and 6,000 RPM.
Canister purge duty cycle is below 3%.Fuel level is between 15% and 85%.
All conditions are present for at least 3 seconds.
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 P1441 will clear after 40 consecutive
warm±up cycles have occurred without a fault.
DTC P1441 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.
Damaged harness ± Inspect the wring harness for
damage. A change in the display will indicate the
location of the fault.
6E±481
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
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, TP sensor 1, TP sensor 2 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 to
increase from about 3 ± 6 g/s at idle to 100 g/s orgreater 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 P1514 cannot be duplicated, the
information included in the Failure Records data can
be useful in determining vehicle mileage since the
DTC was last set.
If it is determined that the DTC occurs intermittently,
performing the DTC P1514 Diagnostic Chart may
isolate the cause of the fault.
DTC P1514 - TPS-MAF Correlation Error
StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
2Was the ªElectric Throttle Control (ETC) System
Checkº performed?
ÐGo to Step 3
Go to ETC
System
Check
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 P1514.
Does the Tech 2 indicate DTC P1514 failed this
ignition?
ÐGo to Step 4
Refer to
Diagnostic
Aids
41. Start the engine.
2. With the engine idling, monitor ªMAF Frequencyº
display on the Tech 2.
Is the ªMAF Frequencyº below the specified value?
6 ~ 10 g/sGo to Step 5Go to Step 8
51. Ignition ªOFFº.
2. Disconnect the MAF sensor connector.
3. Ignition ªONº, engine idling.
4. Using a Tech 2, monitor ªMAF Frequencyº.
Does the Tech 2 indicate a ªMAF Frequencyº at the
specified value?
0g/sGo to Step 6Go to Step 7
6Replace the MAF sensor.
Is the action complete?
ÐVerify repairGo to Step 9
71. Check the MAF harness for incorrect routing near
high voltage components (solenoids, relays,
motors).
2. If incorrect routing is found, correct the harness
routing.
Was a problem found?
ÐVerify repairGo to Step 19
81. With the engine idling, monitor ªMAF Frequencyº
display on the Tech 2.
2. Quickly snap open throttle to wide open throttle
while under a road load and record value.
Does the Tech 2 indicate a ªMAF Frequencyº at the
specified value?
6 ~ 10 g/sGo to Step 6Go to Step 9
91. IgnitionªONº, engine not running.
2. Observe the MAP reading on the Tech 2.
Is the MAP reading less than the specified value?
65kPaGo to Step 10Go to Step 13
6E±487
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1516 Command - Actual TPS Correlation Error
D06RY00111
Circuit Description
The throttle position (TP) sensor circuit provides a
voltage signal relative to throttle position (blade angle).
The throttle blade angle will vary from about 8% at
closed throttle to about 92 % at wide open throttle
(WOT).
The DC motor circuit provides a voltage signal relative
to command throttle position (blade angle).
This DTC detects the difference between actual
throttle position and command throttle position in
steady state.
Conditions for setting the DTC
The ignition is ªONº.
Throttle Actuation mode is normal.
Command Throttle position-Actual Throttle position is
less than 8 % when desired TPS is steady within 0.5
% for 30 seconds within test samples (30 second)
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
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 P1516 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.
DTC P1516 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.
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.
Damaged harness - Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
TP sensor 1, TP sensor 2 display on the Tech2 while
moving connectors and wiring harnesses related to the
sensor.
A change in the display will indicate the location of
the fault. If DTC P1516 cannot be duplicated, the
6E±573
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
An open Bank 1 HO2S 1 signal circuit will set a DTC
P0134 and the Tech 2 will display a constant voltage
between 400-500 mV. A constant voltage below 300 mV
in the sensor circuit (circuit grounded) will set DTC
P0131. A constant voltage above 800 mV in the circuit will
set DTC P0132. Faults in the Bank 2 HO2S 1 signal
circuit will cause DTC 0154 (open circuit), DTC P0151
(grounded circuit), or DTC P0152 (signal voltage high) to
set. A fault in the Bank 1 HO2S 1 heater circuit will cause
DTC P0135 to set. A fault in the Bank 2 HO2S 1 heater
circuit will cause DTC P0155 to set. The PCM can also
detect HO2S response problems. If the response time of
an HO2S is determined to be too slow, the PCM will store
a DTC that indicates degraded HO2S performance.
060RY00127
Catalyst Monitor Heated Oxygen Sensors
Three-way catalytic converters are used to control
emissions of hydrocarbons (HC), carbon monoxide (CO),
and oxides of nitrogen (NOx). The catalyst within the
converters promotes a chemical reaction. This reaction
oxidizes the HC and CO present in the exhaust gas and
converts them into harmless water vapor and carbon
dioxide. The catalyst also reduces NOx by converting it to
nitrogen. The PCM can monitor this process using the
Bank 1 HO2S 2 and the Bank 2 HO2S 2 heated oxygen
sensors. The Bank 1 HO2S 1 and the Bank 2 HO2S 1
sensors produce an output signal which indicates the
amount of oxygen present in the exhaust gas entering the
three-way catalytic converter. The Bank 1 HO2S 2 and
the Bank 2 HO2S 2 sensors produce an output signal
which indicates the oxygen storage capacity of the
catalyst. This indicates the catalyst's ability to efficiently
convert exhaust gases. If the catalyst is operating
efficiently, the Bank 1 HO2S 1 and the Bank 2 HO2S 1
signals will be more active than the signals produced by
the Bank 1 HO2S 2 and the Bank 2 HO2S 2 sensors.
The catalyst monitor sensors operate the same as the
fuel control sensors. The Bank 1 HO2S 2 and the Bank 2
HO2S 2 sensors' main function is catalyst monitoring, but
they also have a limited role in fuel control. If a sensor
output indicates a voltage either above or below the 450
mV bias voltage for an extended period of time, the PCMwill make a slight adjustment to fuel trim to ensure that
fuel delivery is correct for catalyst monitoring.
A problem with the Bank 1 HO2S 2 signal circuit will set
DTC P0137, P0138, or P0140, depending on the specific
condition. A problem with the Bank 2 HO2S 2 signal
circuit will set DTC P0157, P0158, or P0160, depending
on the specific condition. A fault in the heated oxygen
sensor heater element or its ignition feed or ground will
result in lower sensor response. This may cause
incorrect catalyst monitor diagnostic results.
TS24067
TS23365A
Legend
(1) Bank 1 Sensor 1 (Fuel Control)
(2) Catalytic Converter
(3) Bank 1 Sensor 2 (Catalyst Monitor)
(4) Bank 2 Sensor 1 (Fuel Control)
(5) Bank 2 Sensor 2 (Catalyst Monitor)
Intake Air Temperature (IAT) Sensor
The intake air temperature (IAT) sensor is a thermistor
which changes its resistance based on the temperature of
air entering the engine. Low temperature produces a high
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.
7A±10
AUTOMATIC TRANSMISSION (4L30±E)
Checking Transmission Fluid Level
and Condition
Checking fluid level and condition (color and odor) at
regular intervals will provide early diagnosis information
about the transmission. This information may be used to
correct a condition that, if not detected early, could result
in major transmission repairs.
IMPORTANT:When new, automatic transmission fluid
is red in color. As the vehicle is driven, the transmission
fluid will begin to look darker in color. The color may
eventually appear light brown.
A dark brown color with burnt odor may indicate
excessive fluid deterioration and signal a need for fluid
change.
Fluid Level
When adding or changing fluid, use only DEXRON )±III.
Refer to
Maintenance and Lubrication in General
Information section for maintenance information and
servicing interval.
CAUTION: DO NOT OVERFILL.
Overfilling will cause foaming, loss of fluid, abnor-
mal shifting and possible damage to the transmis-
sion.
1. Park the vehicle on level ground and apply the parking
brake firmly.
2. Check fluid level with engine running at idle.
NOTE: Be sure that transmission fluid temperature is
below 30C (86F).
3. Move the selector lever through all gear ranges.
4. Move the selector lever to ªParkº.
5. Let engine idle for 3 minutes and open the overfill
screw (1).
6. Add released transmission fluid until it flows out over
the overfill screw opening.
7. Let engine idle until a fluid temperature between 32C
(90F) and 57C (135F) is reached, then close the
overfill screw (1).
Torque: 38 Nwm (28 lb ft)
NOTE: To prevent fluid leaks, the overfill screw and oil
drain screws gasket must be replaced each time these
screws are removed.NOTE: Check transmission fluid temperature with scan
tool.
Minimum fluid level " 57C (135F)
Maximum fluid level " 32C (90F)
242R200001
CAUTION: Do not open overfill screw with engine
stopped.
CAUTION: DO NOT CHECK FLUID LEVEL UNDER
THESE CONDITIONS:
Immediately after driving at sustained highway
speeds.
In heavy city traffic during hot weather.
If vehicle is towing a trailer.
If the vehicle has been operated under these conditions,
shut the engine off and allow the vehicle to ªcoolº for thirty
(30) minutes. After the cool down period, restart the
vehicle and continue from step 2 above.
7A±27 AUTOMATIC TRANSMISSION (4L30±E)
Changing Transmission Fluid
There is no need to change the transmission fluid unless
the transmission is used under one or more of the
following heavy duty conditions.
A. Repeated short trips
B. Driving on rough roads
C. Driving on dusty roads
D. Towing a trailer
If the vehicle is used under these conditions, change the
fluid every 20,000 miles (32,000 km).
1. Place a large drain pan under the oil pan.
2. Remove the transmission oil drain screw (2) and drain
fluid.
3. Tighten drain screw (2).
Torque: 38 Nwm (28 lb ft)
4. Remove the transmission overfill screw (1) and fill
transmission through overfill screw opening, using
DEXRON)±III ATF.
NOTE: Add transmission fluid until it flows out over the
overfill screw opening.
5. Let engine idle until a fluid temperature between 32C
(90F) and 57C (135F) is reached.
6. Add transmission fluid until it flows out over the overfill
screw opening, then close the overfill screw (1).
Torque: 38 Nwm (28 lb ft)NOTE: To prevent fluid leaks, the overfill screw and oil
drain screws gasket must be replaced each time these
screws are removed.
NOTE: Check transmission fluid temperature with scan
tool.
7. Reset ªOil Life Monitorº data by using Tech 2.
Refer to
Tech 2 OBD II Connection in Transmission
Control System (4L30-E) section.
242R200001
Selector Lever
Inspection
1. Make sure that when the selector lever is shifted from
ªPº to ªLº, a ªclickingº can be felt at each shift position.
Make sure that the gear corresponds to that of the
position plate indicator.
2. Check to see if the selector lever can be shifted as
shown in illustration.
C07RW009
Removal
1. Disconnect battery ground cable.
2. Set ignition Key in ªLOCKº position and selector lever
in ºPº position.
3. Remove knee pads (1), cluster upper cover (2) and
center cluster assembly (3).
740R200021