1998 ISUZU TROOPER Pin IAT sensor

6E±337 ENGINE DRIVEABILITY AND EMISSIONS
0018
Knock Sensor
Insufficient gasoline octane levels may cause detonation
in some engines. Detonation is an uncontrolled explosion
(burn) in the combustion chamber. This uncontrolled
explosion results from a flame front opposite that of the
normal flame front produced by the spark plug. The
rattling sound normally associated with detonation is the
result of two or more opposing pressures (flame fronts)
colliding within the combustion chamber. Light
detonation is sometimes considered normal, but heavy
detonation could result in engine damage.
A knock sensor system is used to control detonation. This
system is designed to retard spark timing up to 20
degrees to reduce detonation in the engine. This allows
the engine to use maximum spark advance to improve
driveability and fuel economy.
The knock sensor system has two major components:

The knock sensor (KS) module.

The knock sensor.
The knock sensor, mounted in the engine block near the
cylinders, detects abnormal vibration in the engine. The
sensor produces an AC output signal of about 10
millivolts. The signal amplitude and frequency are
dependent on the amount of knock being experienced.
The signal voltage increases with the severity of the
knock. This signal voltage is input to the PCM. The PCM
then retards the ignition control (IC) spark timing based
on the KS signal being received.
The PCM determines whether knock is occurring by
comparing the signal level on the KS circuit with the
voltage level on the noise channel. The noise channel
allows the PCM to reject any false knock signal by
indicating the amount of normal engine mechanical noise
present. Normal engine noise varies depending on the
engine speed and load. If the voltage level on the KS
noise channel circuit is below the range considered
normal, DTC P0327 will set, indicating a fault in the KScircuit or the knock sensor. If the PCM determines that an
abnormal minimum or maximum noise level is being
experienced, DTC P0325 will set.
The PCM contains a knock sensor (KS) module. The KS
module contains the circuitry which allows the PCM to
utilize the KS signal and diagnose the KS sensor and the
KS circuitry. If the KS module is missing or faulty, a
continuous knock condition will be indicated, and the
PCM will set DTC P0325.
Although it is a plug-in device, the KS module is not
replaceable. If the KS module is faulty, the entire PCM
must be replaced.
0009
Linear Exhaust Gas Recirculation (EGR)
Control
The PCM monitors the exhaust gas recirculation (EGR)
actual position and adjusts the pintle position accordingly.
The PCM uses information from the following sensors to
control the pintle position:

Engine coolant temperature (ECT) sensor.

Throttle position (TP) sensor.

Mass air flow (MAF) sensor.
Mass Air Flow (MAF) Sensor
The mass air flow (MAF) sensor measures the difference
between the volume and the quantity of air that enters the
engine. ªVolumeº means the size of the space to be filled.
ªQuantityº means the number of air molecules that will fit
into the space. This information is important to the PCM
because heavier, denser air will hold more fuel than
lighter, thinner air. The PCM adjusts the air/fuel ratio as
needed depending on the MAF value. Tech 2 reads the
MAF value and displays it in terms of grams per second
(gm/s). At idle, Tech 2 should read between 4-7 gm/s on a
fully warmed up engine. Values should change quickly on
acceleration. Values should remain stable at any given

6E±347 ENGINE DRIVEABILITY AND EMISSIONS
the secondary ignition circuit to flow through the spark
plug to the ground.
TS24047
Ignition Control PCM Output
The PCM provides a zero volt (actually about 100 mV to
200 mV) or a 5-volt output signal to the ignition control (IC)
module. Each spark plug has its own primary and
secondary coil module (ºcoil-at-plugº) located at the spark
plug itself. When the ignition coil receives the 5-volt signal
from the PCM, it provides a ground path for the B+ supply
to the primary side of the coil-at -plug module. This
energizes the primary coil and creates a magnetic field in
the coil-at-plug module. When the PCM shuts off the
5-volt signal to the ignition control module, the ground
path for the primary coil is broken. The magnetic field
collapses and induces a high voltage secondary impulse
which fires the spark plug and ignites the air/fuel mixture.
The circuit between the PCM and the ignition coil is
monitored for open circuits, shorts to voltage, and shorts
to ground. If the PCM detects one of these events, it will
set one of the following DTCs:

P0351: Ignition coil Fault on Cylinder #1

P0352: Ignition coil Fault on Cylinder #2

P0353: Ignition coil Fault on Cylinder #3

P0354: Ignition coil Fault on Cylinder #4

P0355: Ignition coil Fault on Cylinder #5

P0356: Ignition coil Fault on Cylinder #6
Knock Sensor (KS) PCM Input
The knock sensor (KS) system is comprised of a knock
sensor and the PCM. The PCM monitors the KS signals
to determine when engine detonation occurs. When a
knock sensor detects detonation, the PCM retards the
spark timing to reduce detonation. Timing may also be
retarded because of excessive mechanical engine or
transmission noise.
Powertrain Control Module (PCM)
The PCM is responsible for maintaining proper spark and
fuel injection timing for all driving conditions. To provideoptimum driveability and emissions, the PCM monitors
the input signals from the following components in order
to calculate spark timing:

Engine coolant temperature (ECT) sensor.

Intake air temperature (IAT) sensor.

Mass air flow (MAF) sensor.

PRNDL input from transmission range switch.

Throttle position (TP) sensor.

Vehicle speed sensor (VSS) .

Crankshaft position (CKP) sensor.
Spark Plug
Although worn or dirty spark plugs may give satisfactory
operation at idling speed, they frequency fail at higher
engine speeds. Faulty spark plugs may cause poor fuel
economy, power loss, loss of speed, hard starting and
generally poor engine performance. Follow the
scheduled maintenance service recommendations to
ensure satisfactory spark plug performance. Refer to
Maintenance and Lubrication.
Normal spark plug operation will result in brown to
grayish-tan deposits appearing on the insulator portion of
the spark plug. A small amount of red-brown, yellow, and
white powdery material may also be present on the
insulator tip around the center electrode. These deposits
are normal combustion by-products of fuels and
lubricating oils with additives. Some electrode wear will
also occur. Engines which are not running properly are
often referred to as ªmisfiring.º This means the ignition
spark is not igniting the air/fuel mixture at the proper time.
While other ignition and fuel system causes must also be
considered, possible causes include ignition system
conditions which allow the spark voltage to reach ground
in some other manner than by jumping across the air gap
at the tip of the spark plug, leaving the air/fuel mixture
unburned. Misfiring may also occur when the tip of the
spark plug becomes overheated and ignites the mixture
before the spark jumps. This is referred to as
ªpre-ignition.º
Spark plugs may also misfire due to fouling, excessive
gap, or a cracked or broken insulator. If misfiring occurs
before the recommended replacement interval, locate
and correct the cause.
Carbon fouling of the spark plug is indicated by dry, black
carbon (soot) deposits on the portion of the spark plug in
the cylinder. Excessive idling and slow speeds under
light engine loads can keep the spark plug temperatures
so low that these deposits are not burned off. Very rich
fuel mixtures or poor ignition system output may also be
the cause. Refer to DTC P0172.
Oil fouling of the spark plug is indicated by wet oily
deposits on the portion of the spark plug in the cylinder,
usually with little electrode wear. This may be caused by
oil during break-in of new or newly overhauled engines.
Deposit fouling of the spark plug occurs when the normal
red-brown, yellow or white deposits of combustion by
products become sufficient to cause misfiring. In some
cases, these deposits may melt and form a shiny glaze on
the insulator around the center electrode. If the fouling is
found in only one or two cylinders, valve stem clearances
or intake valve seals may be allowing excess lubricating

6E±349 ENGINE DRIVEABILITY AND EMISSIONS

Damage during re-gapping can happen if the gapping
tool is pushed against the center electrode or the
insulator around it, causing the insulator to crack.
When re-gapping a spark plug, make the adjustment
by bending only the ground side terminal, keeping the
tool clear of other parts.

ºHeat shockº breakage in the lower insulator tip
generally occurs during several engine operating
conditions (high speeds or heavy loading) and may be
caused by over-advanced timing or low grade fuels.
Heat shock refers to a rapid increase in the tip
temperature that causes the insulator material to
crack.
Spark plugs with less than the recommended amount of
service can sometimes be cleaned and re-gapped , then
returned to service. However, if there is any doubt about
the serviceability of a spark plug, replace it. Spark plugs
with cracked or broken insulators should always be
replaced.
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 119
C (246
F).

The IAT is less than 5
C (41
F).

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 for A/C wiring
diagrams and diagnosis for A/C electrical system.
General Description (Exhaust Gas
Recirculation (EGR) System)
EGR Purpose
The exhaust gas recirculation (EGR) system is use to
reduce emission levels of oxides of nitrogen (NOx). NOx
emission levels are caused by a high combustion
temperature. The EGR system lowers the NOx emission
levels by decreasing the combustion temperature.
057RW002
Linear EGR Valve
The main element of the system is the linear EGR valve.
The EGR valve feeds small amounts of exhaust gas back
into the combustion chamber. The fuel/air mixture will be
diluted and combustion temperatures reduced.
Linear EGR Control
The PCM monitors the EGR actual positron and adjusts
the pintle position accordingly. The uses information from
the following sensors to control the pintle position:

Engine coolant temperature (ECT) sensor.

Throttle position (TP) sensor.

Mass air flow (MAF) sensor.
Linear EGR Valve Operation and Results
of Incorrect Operation
The linear EGR valve is designed to accurately supply
EGR to the engine independent of intake manifold
vacuum. The valve controls EGR flow from the exhaust

6A – 60 ENGINE MECHANICAL
VALVE STEM SEAL, VALVE SPRING AND ADJUSTER
REMOVAL
1. Disconnect battery ground cable.
2. Drain engine coolant.
3. Remove the air duct from between air cleaner and
turbocharger.
4. Remove intercooler assembly.
Refer to “Intercooler” in this manual.
5. Remove oil level gauge guide assembly.
6. Disconnect PCV hose.
7. Disconnect EGR vacuum hose.
8. Disconnect harness connectors around the cylinder
head such as the injector, CMP sensor, MAP
sensor, EGR sensor, EVRV, IAT sensor, A/C
compressor, TP stepping motor, TP sensor and fuel
temperature sensor etc.
9. Remove A/C compressor assembly.
10. Remove A/C compressor bracket.
11. Remove generator assembly and take out drivebelt.
12. Remove heat protector, remove exhaust valve
assembly.
13. Remove water cooling hose and lubrication pipe for
turbocharger.
14. Remove turbocharger assembly.
15. Remove hose between thermostat and radiator.
16. Remove noise insulator cover of cylinder head.
NOTE: Do not damage injector harness.
17. Remove high pressure oil pipe.
18. Remove timing belt cover.
19. Remove CMP sensor bracket.
20. Remove timing belt tensioner then remove timing
belt.
21. Remove camshaft pulley.
22. Remove front plate.
23. Remove engine coolant pipe between cylinder
head and water pump.
1
2
3
4
5
6
9
10
7
8
011RW031
Legend
(1) Adjuster
(2) Tappet
(3) Split Collar
(4) Spring Seat Upper
(5) Valve Spring(6) Spring Seat Lower
(7) Valve Stem Seal
(8) Valve Guide
(9) Valve Seat
(10) Valve

6E±1 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
4JX1±TC 3.0L ENGINE
DRIVEABILITY AND EMISSIONS
CONTENTS
Specification 6E±7. . . . . . . . . . . . . . . . . . . . . . . . . .
Tightening Specifications 6E±7. . . . . . . . . . . . . . .
Diagrams and Schematics 6E±8. . . . . . . . . . . . . . . .
ECM Wiring Diagram (1 of 6) 6E±8. . . . . . . . . . . .
ECM Wiring Diagram (2 of 6) 6E±9. . . . . . . . . . . .
ECM Wiring Diagram (3 of 6) 6E±10. . . . . . . . . . . .
ECM Wiring Diagram (4 of 6) 6E±11. . . . . . . . . . . .
ECM Wiring Diagram (5 of 6) 6E±12. . . . . . . . . . . .
ECM Wiring Diagram (6 of 6) 6E±13. . . . . . . . . . . .
ECM Pinouts 6E±14. . . . . . . . . . . . . . . . . . . . . . . . . . .
ECM Pinout Table, 32-Way Connector ± J1
RED ± Upper 6E±14. . . . . . . . . . . . . . . . . . . . . . . . .
ECM Pinout Table, 32-Way Connector ± J1
RED ± Lower 6E±15. . . . . . . . . . . . . . . . . . . . . . . . .
ECM Pinout Table, 32-Way Connector ± J2
BLUE ± Upper 6E±16. . . . . . . . . . . . . . . . . . . . . . . .
ECM Pinout Table, 32-Way Connector ± J2
BLUE ± Lower 6E±17. . . . . . . . . . . . . . . . . . . . . . . .
ECM Pinout Table, 5-Way Connector ± J3 6E±18
Component Locator 6E±19. . . . . . . . . . . . . . . . . . . . .
Sensors and Miscellaneous Component
Locators 6E±21. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Abbreviations Charts 6E±23. . . . . . . . . . . . . . . . . . . .
Diagnosis 6E±24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Strategy-Based Diagnostics 6E±24. . . . . . . . . . . . .
Strategy-Based Diagnostics 6E±24. . . . . . . . . . . . .
DTC Stored 6E±24. . . . . . . . . . . . . . . . . . . . . . . . . . .
No DTC 6E±24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
No Matching Symptom 6E±24. . . . . . . . . . . . . . . . .
Intermittents 6E±24. . . . . . . . . . . . . . . . . . . . . . . . . .
No Trouble Found 6E±24. . . . . . . . . . . . . . . . . . . . .
Verifying Vehicle Repair 6E±24. . . . . . . . . . . . . . . .
General Service Information 6E±25. . . . . . . . . . . . . .
Serviceability Issues 6E±25. . . . . . . . . . . . . . . . . . .
Visual/Physical Engine Compartment
Inspection 6E±25. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basic Knowledge of Tools Required 6E±25. . . . . .
Serial Data Communications 6E±25. . . . . . . . . . . . . .
Class II Serial Data Communications 6E±25. . . . .
On-Board Diagnostic (OBD) 6E±25. . . . . . . . . . . . . .
On-Board Diagnostic Tests 6E±25. . . . . . . . . . . . .
Comprehensive Component Monitor
Diagnostic Operation 6E±25. . . . . . . . . . . . . . . . . .
Common OBD Terms 6E±26. . . . . . . . . . . . . . . . . .
The Diagnostic Executive 6E±26. . . . . . . . . . . . . . .
DTC Types 6E±26. . . . . . . . . . . . . . . . . . . . . . . . . . .
Verifying Vehicle Repair 6E±27. . . . . . . . . . . . . . . . Reading Flash Diagnostic Trouble Codes 6E±27.
Reading Diagnostic Trouble Codes Using
a TECH 2 6E±28. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tech 2 Scan Tool 6E±29. . . . . . . . . . . . . . . . . . . . . .
Getting Started 6E±30. . . . . . . . . . . . . . . . . . . . . . . .
DTC Modes 6E±32. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC Information Mode 6E±32. . . . . . . . . . . . . . . . .
Injector Test 6E±32. . . . . . . . . . . . . . . . . . . . . . . . . .
EGR Valve Test 6E±32. . . . . . . . . . . . . . . . . . . . . . .
Rail Pressure Control Valve Test 6E±32. . . . . . . . .
Injector Balance Test 6E±32. . . . . . . . . . . . . . . . . . .
Data Programming in Case of ECM Change 6E±32
Rail Pressure Sensor Programming 6E±33. . . . . .
Injector Group Sign Programming
(Injector Change) 6E±33. . . . . . . . . . . . . . . . . . . . .
On-Board Diagnostic (OBD) System Check 6E±35.
Circuit Description 6E±37. . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 6E±37. . . . . . . . . . . . . . . . . . . . . . . .
Engine Control Module ECM Diagnosis 6E±39. . . .
Multiple ECM Information Sensor DTCS Set 6E±39
Circuit Description 6E±39. . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 6E±39. . . . . . . . . . . . . . . . . . . . . . . .
EGR (Exhaust Gas Recirculation) Diagnosis 6E±41
Tech 2 Data Definitions and Ranges 6E±41. . . . . . .
Typical Scan Data Values 6E±41. . . . . . . . . . . . . . . .
Test Conditions 6E±41. . . . . . . . . . . . . . . . . . . . . . . .
4JX1-TC Engine (Automatic and Manual
Transmission) 6E±42. . . . . . . . . . . . . . . . . . . . . . . .
No Malfunction Indicator Lamp (MIL) 6E±44. . . . . . .
Circuit Description 6E±44. . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 6E±44. . . . . . . . . . . . . . . . . . . . . . . .
Malfunction Indicator Lamp (MIL) ªONº
Steady 6E±47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit description 6E±47. . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 6E±47. . . . . . . . . . . . . . . . . . . . . . . .
Engine Cranks But Will Not Run 6E±49. . . . . . . . . . .
Circuit Description 6E±49. . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 6E±49. . . . . . . . . . . . . . . . . . . . . . . .
Exhaust Gas Recirculation (EGR) System
Check 6E±52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Description 6E±52. . . . . . . . . . . . . . . . . . . . .
ECM Diagnostic Trouble Codes 6E±54. . . . . . . . . . .
ECM Diagnostic Trouble Codes 6E±54. . . . . . . . .
Diagnostic Trouble Code (DTC) P0107
(Flash DTC 34)
MAP Sensor Circuit Low Voltage 6E±56. . . . . . . . . .

6E±23 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Abbreviations Charts
List of abbreviations which may be used in this section.
Abbreviations
TermAbbreviationsTerm
A/CAir ConditionerBLKBlack
A/TAutomatic TransmissionBLUBlue
ACCAccessoryBRNBrown
APAccel PositionGRNGreen
ASMAssemblyGRYGray
CKPCrank PositionLT BLULight Blue
CMPCam PositionLT GRNLight Green
DLCData Link ConnectorORNOrange
DTCDiagnosis Trouble CodePNKPink
DVMDigital Volt MeterREDRed
ECMEngine Control ModuleVIOViolet
ECTEngine Coolant TemperatureWHTWhite
EGRExhaust Gas RecircurationYELYellow
EVRVElectric Vacuum Regulating Valve
EXHExhaust
FTFuel Temperature
IATIntake Air Temperature
IGIgnition
ITPIntake Throttle Position
M/TManual Transmission
MAPManifold Absolute Pressure
MILMulfunction Indicator Lamp
OBDOn-Board Diagnostic
OTOil Temperature
QOSQuick on Start System
QWSQuick Warming-Up System
RPRail Pressure
RPCVRail Pressure Control Valve
SRSSupplemental Restraint System
STStart
SWSwitch
TEMPTemperature
TODTorque on Demand
VSSVehicle Speed Sensor
VSVVacuum Switching Valve
HEUIHydraulically Actuated Electronically Controlled Unit
InjectorInjector

6E±25 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
General Service Information
Serviceability Issues
Non-OEM Parts
All of the OBD diagnostics have been calibrated to run
with OEM parts. Accordingly, if commercially sold sensor
or switch is installed, it makes a wrong diagnosis and turn
on the MIL (ªCheck Engineº lamp).
Aftermarket electronics, such as cellular phones,
stereos, and anti-theft devices, may radiate EMI into the
control system if they are improperly installed. This may
cause a false sensor reading and turn on the MIL (ªCheck
Engineº lamp).
Poor Vehicle Maintenance
The sensitivity of OBD diagnostics will cause the MIL
(ªCheck Engineº lamp) to turn on if the vehicle is not
maintained properly. Restricted oil filters, fuel filters, and
crankcase deposits due to lack of oil changes or improper
oil viscosity can trigger actual vehicle faults that were not
previously monitored prior to OBD. Poor vehicle
maintenance can not be classified as a ªnon-vehicle
faultº, but with the sensitivity of OBD diagnostics, vehicle
maintenance schedules must be more closely followed.
Related System Faults
Many of the OBD system diagnostics will not run if the
ECM detects a fault on a related system or component.
Visual/Physical Engine Compartment
Inspection
Perform a careful visual and physical engine
compartment inspection when performing any diagnostic
procedure or diagnosing the cause of an emission test
failure. This can often lead to repairing a problem without
further steps. Use the following guidelines when
performing a visual/physical inspection:

Inspect all vacuum hoses for punches, cuts,
disconnects, and correct routing.

Inspect hoses that are difficult to see behind other
components.

Inspect all wires in the engine compartment for proper
connections, burned or chafed spots, pinched wires,
contact with sharp edges or contact with hot exhaust
manifolds or pipes.
Basic Knowledge of Tools Required
NOTE: Lack of basic knowledge of this powertrain when
performing diagnostic procedures could result in an
incorrect diagnosis or damage to powertrain
components. Do not attempt to diagnose a powertrain
problem without this basic knowledge.
A basic understanding of hand tools is necessary to effec-
tively use this section of the Service Manual.
Serial Data Communications
Class II Serial Data Communications
This vehicle utilizes the ªClass IIº communication system.
Each bit of information can have one of two lengths: longor short. This allows vehicle wiring to be reduced by
transmitting and receiving multiple signals over a single
wire. The messages carried on Class II data streams are
also prioritized. If two messages attempt to establish
communications on the data line at the same time, only
the message with higher priority will continue. The device
with the lower priority message must wait.
On this vehicle the Tech 2 displays the actual values for
vehicle parameters. It will not be necessary to perform
any conversions from coded values to actual values.
On-Board Diagnostic (OBD)
On-Board Diagnostic Tests
A diagnostic test is a series of steps, the result of which is
a pass or fail reported to the diagnostic executive. When
a diagnostic test reports a pass result, the diagnostic
executive records the following data:

The diagnostic test has been completed since the last
ignition cycle.

The diagnostic test has passed during the current
ignition cycle.

The fault identified by the diagnostic test is not
currently active.
When a diagnostic test reports a fail result, the diagnostic
executive records the following data:

The diagnostic test has been completed since the last
ignition cycle.

The fault identified by the diagnostic test is currently
active.

The fault has been active during this ignition cycle.

The operating conditions at the time of the failure.
Comprehensive Component Monitor
Diagnostic Operation
Comprehensive component monitoring diagnostics are
required to operate engine properly.
Input Components:
Input components are monitored for circuit continuity and
out-of-range values. This includes rationality checking.
Rationality checking refers to indicating a fault when the
signal from a sensor does not seem reasonable. Accel
Position (AP) sensor that indicates high throttle position
at low engine loads or MAP voltage. Input components
may include, but are not limited to the following sensors:

Intake Air Temperature (IAT) Sensor

Crankshaft Position (CKP) Sensor

Intake throttle Position (ITP) Sensor

Engine Coolant Temperature (ECT) Sensor

Camshaft Position (CMP) Sensor

Manifold absolute Pressure (MAP) Sensor

Accel Position Sensor

Fuel Temp Sensor

Rail Pressure Sensor

Oil Temp Sensor

EGR Pressure Sensor

Vehicle Speed Sensor

6E±131 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P1403 ± EGR EVRV Fault

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Check the EVRV circuit.
Was the EVRV circuit darmage?
Ð
Replace the
EVRV circuit
Go to Step 3
31. Start the engine.
2. Monitor the MAP signal with a scan tool while idling.
3. While idling, jab the accelerator pedal about halfway
down and immediately let the engine return to idle.
Did the MAP value on the scan tool show an immediate
large change?
ÐGo to Step 5Go to Step 4
4Replace the MAP sensor.
Is the action complete?
ÐVerify repairÐ
51. Inspect the exhaust system for modification of
original installed parts or leaks.
2. If a problem was found, repair exhaust system as
necessary.
Was a condition present that required repair?
ÐGo to Step 8Go to Step 6
61. Remove the EGR valve.
2. Visually and physically inspect the pintle, valve
passages and the adapter for excessive deposits or
any kind of a restriction.
3. If a problem is found, clean or replace EGR system
components as necessary.
Was a condition present that required repair?
ÐGo to Step 8Go to Step 7
71. Inspect the EGR passages for a blockage caused
by excessive deposits or other damage.
2. If a problem is found, correct the condition as
necessary.
Was a condition present that required repair?
ÐGo to Step 8
Refer to
Diagnostic
Aids
81. Review and record the scan tool Failure Records
data.
2. Clear DTC and monitor the scan tool System Info
Screen while operating the vehicle as specified in
ªDiagnostic Aids.º
3. Using a scan tool, monitor ªDTCº info for DTC
P1403 until the DTC P1403 test runs.
4. Note the test result.
Does the scan tool indicate DTC P1403 failed this
ignition?
Ð
Go to the last
step
completed in
this
diagnostic
chart
Repair
complete