
6E±76
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Exhaust Gas Recirculation (EGR)
Diagnosis
An EGR flow check diagnosis of the linear EGR system is
covered by DTC P0401. Pintle position error diagnosis is
covered by DTC P0402, P0404, P1404, P0405, P0406. If
EGR diagnostic trouble codes P0401 and/or P0402,
P0404, P1404, P0405, P0406 are encountered, refer to
the DTC charts.
Engine Tech 2 Data Definitions and
Ranges
A/C CLUTCH ± Tech 2 Displays ON or OFF ±
Indicates whether the PCM has commanded the A/C
clutch ON. Used in A/C system diagnostic.
A/C REQUEST Ð Tech 2 Displays YES or NO Ð
Indicates the state of the A/C request input circuit from the
HVAC controls. The PCM uses the A/C request signal to
determine whether A/C compressor operation is being
requested.
AIR/FUEL RATIO Ð Tech 2 Range 0.0-25.5 Ð
Air/fuel ratio indicates the PCM commanded value. In
closed loop, the air/fuel ratio should normally be
displayed around ª14.2-14.7º. A lower air/fuel ratio
indicates a richer commanded mixture, which may be
seen during power enrichment or TWC protection modes.
A higher air/fuel ratio indicates a leaner commanded
mixture. This can be seen during deceleration fuel mode.
AP1 ÐTech 2 Range 0%-100% Ð
AP (accelerator pedal) angle is computed by the PCM
from the AP sensor voltage. AP angle should display
ª13%º at idle and ª85-89%º at wide open throttle.
AP2 ÐTech 2 Range 0%-100% Ð
AP (accelerator pedal) angle is computed by the PCM
from the AP sensor voltage. AP angle should display
ª85-89%º at idle and ª11-15%º at wide open throttle.
AP3 ÐTech 2 Range 0%-100% Ð
AP (accelerator pedal) angle is computed by the PCM
from the AP sensor voltage. AP angle should display
ª85-89%º at idle and ª32-36%º at wide open throttle.
BAROMETRIC PRESSURE Ð Tech 2 Range 10-105
kPa/0.00-5.00 Volts Ð
The barometric pressure reading is determined from the
MAP sensor signal monitored during key up and wide
open throttle (WOT) conditions. The barometric pressure
is used to compensate for altitude differences and is
normally displayed around ª61-104º depending on
altitude and barometric pressure.
CHECK TRANS LAMP Ð AUTO TRANSMISSION Ð
Indicates the need to check for a DTC with the Tech 2
when the lamp is flashing 0.2 seconds ON and 0.2
seconds OFF.
DESIRED EGR POS. Ð Tech 2 Range 0%-100% Ð
Represents the EGR pintle position that the PCM is
commanding.
DESIRED IDLE Ð Tech 2 Range 0-3187 RPM Ð
The idle speed that the PCM is commanding. The PCM
will compensate for various engine loads based on engine
coolant temperature, to keep the engine at the desired
speed.ECT Ð (Engine Coolant Temperature) Tech 2
Range ±40C to 151C (±40F to 304F) Ð
The engine coolant temperature (ECT) is mounted in the
coolant stream and sends engine temperature
information to the PCM. The PCM applies 5 volts to the
ECT sensor circuit. The sensor is a thermistor which
changes internal resistance as temperature changes.
When the sensor is cold (high resistance), the PCM
monitors a high signal voltage and interprets that as a cold
engine. As the sensor warms (decreasing resistance),
the voltage signal will decrease and the PCM will interpret
the lower voltage as a warm engine.
EGR DUTY CYCLE Ð Tech 2 Range 0%-100% Ð
Represents the EGR valve driver PWM signal from the
PCM. A duty cycle of 0% indicates that no EGR flow is
being commanded; a 100% duty cycle indicates
maximum EGR flow commanded.
EGR FEEDBACK Ð Tech 2 Range 0.00-5.00 Volts Ð
Indicates the EGR pintle position sensor signal voltage
being monitored by the PCM. A low voltage indicates a
fully extended pintle (closed valve); a voltage near 5 volts
indicates a retracted pintle (open valve).
ENGINE LOAD Ð Tech 2 Range 0%-100% Ð
Engine load is calculated by the PCM from engine speed
and MAF sensor readings. Engine load should increase
with an increase in RPM or air flow.
ENGINE RUN TIME Ð Tech 2 Range
00:00:00-99:99:99 Hrs:Min:Sec Ð
Indicates the time elapsed since the engine was started.
If the engine is stopped, engine run time will be reset to
00:00:00.
ENGINE SPEED Ð Range 0-9999 RPM Ð
Engine speed is computed by the PCM from the 58X
reference input. It should remain close to desired idle
under various engine loads with engine idling.
EVAP PURGE PWM Ð Tech 2 Range 0%-100% Ð
Represents the PCM commanded PWM duty cycle of the
EVAP purge solenoid valve. ª0%º displayed indicates no
purge; ª100%º displayed indicates full purge.
FUEL PUMP Ð Tech 2 Displays ON or OFF Ð
Indicates the PCM commanded state of the fuel pump
relay driver circuit.
HO2S BANK 1, SEN. 1
Ð Tech 2 Range 0-1132 mV Ð
Represents the fuel control exhaust oxygen sensor
output voltage. Should fluctuate constantly within a range
between 10 mV (lean exhaust) and 1000 mV (rich
exhaust) while operating in closed loop.
HO2S BANK 1, SEN. 2
Ð Tech 2 Range 0-1000mV Ð
Monitors the exhaust oxygen sensor output voltage. The
PCM monitors the operating efficiency of catalytic
converter by comparing the output voltages of sensor 1
and sensor 2 in this bank. If the catalytic converter is
operating efficiently, the output voltage of sensor 1 will
give a greater fluctuation than that of sensor 2. If the
PCM detects an abnormal level of voltage fluctuation
from sensor 2, a DTC P0420 will be set, indicating that the
catalytic converter for this bank is no longer operating
efficiently.

6E±80
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Tech 2
ParameterRefer To Typical Data
Values
(2500 RPM) Typical Data
Values (IDLE) Units Displayed Data List
EGR Duty
CycleEnginePercent0%0%General Description and
Operation, Linear EGR
Operation and Results of
Incorrect Operation
EGR
FeedbackEngineVolts0.45-0.800.45-0.80Ð
EGR
NormalizedEnginePercent0%0%Ð
Engine LoadEnginePercent2.0% - 5.5%8.0% - 16.0%General Description and
Operation, Mass Air Flow
(MAF) Sensor
Time From
StartEngineSecVaries. Resets
at each engine
start.Varies. Resets
at each engine
start.
Ð
Engine SpeedEngineRPMWithin ±50 to
+100 of
ªDesired IdleºActual engine
speed
Ð
EVAP Purge
SolenoidEnginePercent0%0%Diagnosis, EVAP
Emission Canister Purge
Valve Check
EVAP Vent
ValveEngineOn/OffOffOffDiagnosis, EVAP Canister
Purge Solenoid and
EVAP Vacuum Switch
and Visual Check; DTCs:
P1441, P1442
Fuel System
StatusEngineOpen
Loop/Closed
LoopClosed LoopClosed LoopGeneral Description
Fuel LevelEnginePercentÐÐEngine Fuel
Fuel Level
SensorEngineVoltsÐÐEngine Fuel
Fuel Tank
(Vapor)EngineVolts1.02 ± 1.861.02 ± 2.57General Description and
Operation
Pressure
Sensorin. H2OÐÐ
Fuel PumpEngineOn/OffOnOnEngine Fuel
HO2S Bank 1
Sen.1
(millivolts)O2
Sensor
DataMillivolts50-950
changing
quickly50-950, always
changing
quicklyGeneral Description and
Operation, Fuel control
HO2S
HO2S Bank 1
Sen.2
(millivolts)
(Auto Trans)O2
Sensor
DataMillivolts200-700
changing slowly250-650
changing slowlyGeneral Description and
Operation, Fuel Metering
System
HO2S Bank 1
Sen.2
(millivolts)
(Manual
Trans)O2
Sensor
DataMillivolts50-950
changing
quickly50-950
changing
quicklyGeneral Description and
Operation, Fuel Metering
System
HO2S Bank 1
Sen.3
(millivolts)
(Manual
Trans)O2
Sensor
DataMillivolts200-700
changing slowly250-650
changing slowlyGeneral Description and
Operation, Catalyst
Monitor Heated Oxygen
Sensor (Manual Trans)

6E±130
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTCIlluminate
RPL
(Reduced
Power
Lamp) Illuminate
MIL
(Check
Engine
Lamp) Type Description
P1290ETC Forced Idle ModeAYe sYe s
P1295ETC Power Management ModeAYe sYe s
P1299ETC Forced Engine Shutdown in ModeAYe sYe s
P1310ION Sensing Module DiagnosticAYe sNo
P1311ION Sensing Module SEC 1 Line Circuit FaultAYe sNo
P1312ION Sensing Module SEC 2 Line Circuit FaultAYe sNo
P1326ION Sensing Module Combustion Quality circuitAYe sNo
P1340ION Sensing Module ± Cylinder SynchronizationBYe sNo
P1404EGR Range/Performance (Closed Valve)BYe sNo
P1441EVAP Control System Continuous Open Purge FlowBYe sNo
P1514TPS±MAF CorrelationAYe sNo
P1515Command±Acrual TPS CorrelationAYe sNo
P1516Command±Acrual TPS Correlation ErrorAYe sNo
P1523Throttle Actuator Control Return PerformanceDNoNo
P1625PCM/ECM System ResetDNoNo
P1635Reference Voltage #1 CircuitDNoNo
P1639Reference Voltage #2 CircuitDNoNo
P1640ODM Output circuit FaultDNoNo
P1650QDM Output Circuit FaultDNoNo

6E±239
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. This step determines if DTC P0201 is the result of a
hard failure or an intermittent condition.
5. A special injector test connector is provided so that
the injectors can be electrically tested without
removal of the manifold. The test connector can be
identified by the blue connector lock which is
tethered to the wiring harness. If the light for
cylinder 1 is ªONº steady before cranking the engine
as well as while cranking the engine, then the
injector driver circuit is shorted to ground.
If the test light blinks while cranking, the PCM and
the wiring to the injectors are OK. The Fuel Injector
Coil Test Procedure will check if the injectors are
faulty.
R321054
7. Because the test light was ªONº steady, voltage to
the injector is OK, but the driver circuit is grounded
at all times. This step determines if the circuit is
shorted to ground or the PCM is faulty.
9. The reading should be about 12-14.
10.Locating the open in the harness or in the injector
will require removal of the manifold to provide
access.
DTC P0201 ± Injector 1 Control Circuit
StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Will the engine start?
ÐGo to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0201 reset?
ÐGo to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
ªONº and the engine ªOFFº and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0201 reset?
ÐGo to Step 5
Go to
Diagnostic
Aids
51. Engine ªOFFº.
2. Disconnect the injector connector.
3. Install an injector test light J-39021-65 on the
injector test connector.
4. Crank the engine and note the light.
Does the injector test light blink?
Ð
Go to Fuel
Injector Coil
Test
Procedure
Go to Step 6

6E±242
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. This step determines if DTC P0202 is the result of a
hard failure or an intermittent condition.
5. A special injector test connector is provided so that
the injectors can be electrically tested without
removal of the manifold. The test connector can be
identified by the blue connector lock which is
tethered to the wiring harness. If the light for
cylinder 2 is ªONº steady before cranking the engine
as well as while cranking the engine, then the
injector driver circuit is shorted to ground.
If the test light blinks while cranking, the PCM and
the wiring to the injectors are OK. The Fuel Injector
Coil Test Procedure will check if the injectors are
faulty.
R321055
7. Because the test light was ªONº steady, voltage to
the injector is OK, but the driver circuit is grounded
at all times. This step determines if the circuit is
shorted to ground or the PCM is faulty.
9.The reading should be about 12-14.
10.Locating the open in the harness or in the injector
will require removal of the manifold to provide
access.
DTC P0202 ± Injector 2 Control Circuit
StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Will the engine start?
ÐGo to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0202 reset?
ÐGo to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
ªONº and the engine ªOFFº and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0202 reset?
ÐGo to Step 5
Go to
Diagnostic
Aids
51. Engine ªOFFº.
2. Disconnect the injector test connector.
3. Install an injector test light J-39021-65 on injector
connector.
4. Crank the engine and note the light.
Does the cylinder 2 test light blink?
Ð
Go to Fuel
Injector Coil
Test
Procedure
Go to Step 6

6E±245
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. This step determines if DTC P0203 is the result of a
hard failure or an intermittent condition.
5. A special injector test connector is provided so that
the injectors can be electrically tested without
removal of the manifold. The test connector can be
identified by the blue connector lock which is
tethered to the wiring harness. If the light for
cylinder 3 is ªONº steady before cranking the engine
as well as while cranking the engine, then the
injector driver circuit is shorted to ground.
If the test light blinks while cranking, the PCM and
the wiring to the injectors are OK. The Fuel Injector
Coil Test Procedure will check if the injectors are
faulty.
R321056
7. Because the test light was ªONº steady, voltage to
the injector is OK, but the driver circuit is grounded
at all times. This step determines if the circuit is
shorted to ground or the PCM is faulty.
9. The reading should be about 12-14.
10.Locating the open in the harness or in the injector
will require removal of the manifold to provide
access.
DTC P0203 ± Injector 3 Control Circuit
StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Will the engine start?
ÐGo to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0203 reset?
ÐGo to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
ªONº and the engine ªOFFº and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0203 reset?
ÐGo to Step 5
Go to
Diagnostic
Aids
51. Engine ªOFFº.
2. Disconnect the injector test connector .
3. Install an injector test light J-39021-65 on injector
connector.
4. Crank the engine and note the light.
Does the cylinder 3 test light blink?
Ð
Go to Fuel
Injector Coil
Test
Procedure
Go to Step 6

6E±248
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. This step determines if DTC P0204 is the result of a
hard failure or an intermittent condition.
5. A special injector test connector is provided so that
the injectors can be electrically tested without
removal of the manifold. The test connector can be
identified by the blue connector lock which is
tethered to the wiring harness. If the light for
cylinder 4 is ªONº steady before cranking the engine
as well as while cranking the engine, then the
injector driver circuit is shorted to ground.
If the test light blinks while cranking, the PCM and
the wiring to the injectors are OK. The Fuel Injector
Coil Test Procedure will check if the injectors are
faulty.
R321057
7. Because the test light was ªONº steady, voltage to
the injector is OK, but the driver circuit is grounded
at all times. This step determines if the circuit is
shorted to ground or the PCM is faulty.
9. The reading should be about 12-14.
10.Locating the open in the harness or in the injector
will require removal of the manifold to provide
access.
DTC P0204 ± Injector 4 Control Circuit
StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Will the engine start?
ÐGo to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0204 reset?
ÐGo to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
ªONº and the engine ªOFFº and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0204 reset?
ÐGo to Step 5
Go to
Diagnostic
Aids
51. Engine ªOFFº.
2. Disconnect the injector test connector.
3. Install an injector test light J-39021-65 on injector
connector.
4. Crank the engine and note the light.
Does the cylinder 4 test light blink?
Ð
Go to Fuel
Injector Coil
Test
Procedure
Go to Step 6

6E±251
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. This step determines if DTC P0205 is the result of a
hard failure or an intermittent condition.
5. A special injector test connector is provided so that
the injectors can be electrically tested without
removal of the manifold.The test connector can be
identified by the blue connector lock which is
tethered to the wiring harness. If the light for
cylinder 5 is ªONº steady before cranking the engine
as well as while cranking the engine, then the
injector driver circuit is shorted to ground.
If the test light blinks while cranking, the PCM and
the wiring to the injectors are OK. The Fuel Injector
Coil Test Procedure will check if the injectors are
faulty.
R321058
7. Because the test light was ªONº steady, voltage to
the injector is OK, but the driver circuit is grounded
at all times. This step determines if the circuit is
shorted to ground or the PCM is faulty.
9. The reading should be about 12-14.
10.Locating the open in the harness or in the injector
will require removal of the manifold to provide
access.
DTC P0205 ± Injector 5 Control Circuit
StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Will the engine start?
ÐGo to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0205 reset?
ÐGo to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
ªONº and the engine ªOFFº and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0205 reset?
ÐGo to Step 5
Go to
Diagnostic
Aids
51. Engine ªOFFº.
2. Disconnect the injector test connector.
3. Install an injector test light J-39021-65 on injector
connector.
4. Crank the engine and note the light.
Does the cylinder 5 test light blink?
Ð
Go to Fuel
Injector Coil
Test
Procedure
Go to Step 6