Pin IAT sensor ISUZU TROOPER 1998 Service Owner's Manual

6E±69 ENGINE DRIVEABILITY AND EMISSIONS
HO2S BANK2, SEN. 1ÐTech 2 Range 0-1132 mVÐ
Represents the fuel control exhaust oxygen sensor
output voltage. Should fluctuate constantly within a range
between 10mV (lean exhaust) and 1000 mV (rich
exhaust) while operating in closed loop.
HO2S BANK 1, SEN. 1ÐTech 2 Displays NOT
READY or READYÐ
Indicates the status of the exhaust oxygen sensor. The
Tech 2 will indicate that the exhaust oxygen sensor is
ready when the PCM detects a fluctuating HO2S voltage
sufficient to allow closed loop operation. This will not
occur unless the exhaust oxygen sensor is warmed up.
HO2S BANK 2, SEN. 1 Ð Tech 2 Displays NOT
READY or READY Ð
Indicates the status of the exhaust oxygen sensor. The
Tech 2 will indicate that the exhaust oxygen sensor is
ready when the PCM detects a fluctuating HO2S voltage
sufficient to allow closed loop operation. This will not
occur unless the exhaust oxygen sensor is warmed up.
HO2S WARM UP TIME BANK 1, SEN. 1/BANK 2
SEN. 1 Ð Tech 2 Range 00:00:00-99:99:99
HRS:MIN:SEC Ð
Indicates warm-up time for each HO2S. The HO2S
warm-up time is used for the HO2S heater test. The PCM
will run the heater test only after a cold start (determined
by engine coolant and intake air temperature at the time
of start-up) and only once during an ignition cycle. When
the engine is started the PCM will monitor the HO2S
voltage. When the HO2S voltage indicates a sufficiently
active sensor, the PCM looks at how much time has
elapsed since start-up. If the PCM determines that too
much time was required for the HO2S to become active,
a DTC will set. If the engine was warm when started,
HO2S warm-up will the display ª00:00:00º.
IAC POSITION Ð Tech 2 Range 0-255 Counts Ð
Displays the commanded position of the idle air control
pintle in counts. A larger number of counts means that
more air is being commanded through the idle air
passage. Idle air control should respond fairly quickly to
changes in engine load to maintain desired idle RPM.
IAT (INTAKE AIR TEMPERATURE) Ð Tech 2 Range
±40
C to 151
C (±40
F to 304
F) Ð
The PCM converts the resistance of the intake air
temperature sensor to degrees. Intake air temperature
(IAT) is used by the PCM to adjust fuel delivery and spark
timing according to incoming air density.
IGNITION 1 Ð Tech 2 Range 0-25.5 Volts Ð
This represents the system voltage measured by the
PCM at its ignition feed.
INJ. PULSE BANK 1/INJ. PULSE BANK 2 Ð Tech 2
Range 0-1000 msec. Ð
Indicates the amount of time the PCM is commanding
each injector ªONº during each engine cycle. A longer
injector pulse width will cause more fuel to be delivered.
Injector pulse width should increase with increased
engine load.KS NOISE CHANNEL (Knock Sensor) Ð
Indicates the output from the KS noise channel. There is
always some electrical noise in an engine compartment
and to avoid mistaking this as engine knock, the output
from the knock sensor is compared to the output from the
noise channel. A knock condition is not set unless the
knock sensor output is greater than the noise channel
output.
LONG TERM FUEL TRIM BANK 1/BANK 2 Ð
The long term fuel trim is derived from the short term fuel
trim values and represents a long term correction of fuel
delivery for the bank in question. A value of 0% indicates
that fuel delivery requires no compensation to maintain
the PCM commanded air/fuel ratio. A negative value
significantly below 0% indicates that the fuel system is
rich and fuel delivery is being reduced (decreased injector
pulse width). A positive value significantly greater than
0% indicates that a lean condition exists and the PCM is
compensating by adding fuel (increased injector pulse
width). Because long term fuel trim tends to follow short
term fuel trim, a value in the negative range due to
canister purge at idle should not be considered unusual.
Fuel trim values at maximum authority may indicate an
excessively rich or lean system.
LOOP STATUS Ð Tech 2 Displays OPEN or
CLOSED Ð
ªCLOSEDº indicates that the PCM is controlling fuel
delivery according to oxygen sensor voltage. In ªOPENº
the PCM ignores the oxygen sensor voltage and bases
the amount of fuel to be delivered on TP sensor, engine
coolant, and MAF sensor inputs only.
MAF Ð Tech 2 Range 0.0-512 gm/s Ð
MAF (mass air flow) is the MAF input frequency
converted to grams of air per second. This indicates the
amount of air entering the engine.
MAP Ð Tech 2 Range 10-105 kPa (0.00-4.97 Volts)
Ð
The manifold absolute pressure (MAP) sensor measures
the change in the intake manifold pressure from engine
load, EGR flow, and speed changes. As intake manifold
pressure increases, intake vacuum decreases, resulting
in a higher MAP sensor voltage and kPa reading. The
MAP sensor signal is used to monitor intake manifold
pressure changes during the EGR flow test, to update the
BARO reading, and as an enabling factor for several of
the diagnostics.
MIL Ð Tech 2 Displays ON or OFF Ð
Indicates the PCM commanded state of the malfunction
indicator lamp.
POWER ENRICHMENT Ð Tech 2 Displays ACTIVE
or INACTIVE Ð
ªACTIVEº displayed indicates that the PCM has detected
conditions appropriate to operate in power enrichment
mode. The PCM will command power enrichment mode
when a large increase in throttle position and load is
detected. While in power enrichment mode, the PCM will
increase the amount of fuel delivered by entering open
loop and increasing the injector pulse width. This is done
to prevent a possible sag or hesitation from occurring
during acceleration.

6E±251 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1508 IAC System Low RPM
T321115
Circuit Description
The powertrain control module (PCM) controls engine
idle speed by adjusting the position of the idle air control
(IAC) motor pintle. The IAC is a bi-directional stepper
motor driven by two coils. The PCM applies current to the
IAC coils in steps (counts) to extend the IAC pintle into a
passage in the throttle body to decrease air flow. The
PCM reverses the current to retract the pintle, increasing
air flow. This method allows highly accurate control of idle
speed and quick response to changes in engine load. If
the PCM detects a condition where too low of an idle
speed is present and the PCM is unable to adjust idle
speed by increasing the IAC counts, DTC P1508 will set,
indicating a problem with the idle control system.
Conditions for Setting the DTC

No Tech 2 test is being run.

None of these DTCs are set: TP sensor, VSS, ECT,
EGR, fuel system, MAF, MAP, IAT, canister purge,
injector control or ignition control.

Barometric pressure is above 75 kPa.

Engine coolant temperature (ECT) is above 50
C
(120
F).

Engine speed is more than 100-200 RPM lower than
desired idle, based upon coolant temperature.

The engine has been running for at least 125 seconds.

Vehicle speed is less than 1 mph.

Canister purge duty cycle is above 10%.

Ignition voltage is between 9.5 volts and 16.7 volts.
The throttle is closed.

Engine speed is lower than desired idle.

All of the above conditions are met for 10 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

DTC P1508 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 or IAC motor ± 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 for damage.

Restricted air intake 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 IAC
passage or throttle bore, excessive deposits in the IAC

6E±254
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1509 IAC System High RPM
T321115
Circuit Description
The powertrain control module (PCM) controls engine
idle speed by adjusting the position of the idle air control
(IAC) motor pintle. The IAC is a bi-directional stepper
motor driven by two coils. The PCM applies current to the
IAC coils in steps (counts) to extend the IAC pintle into a
passage in the throttle body to decrease air flow. The
PCM reverses the current to retract the pintle, increasing
air flow. This method allows highly accurate control of idle
speed and quick response to changes in engine load. If
the PCM detect a condition where too high of an idle
speed is present and the PCM is unable to adjust idle
speed by increasing the IAC counts, DTC P1509 will set,
indicating a problem with the idle control system.
Conditions for Setting the DTC

No Tech 2 test is being run.

None of these DTCs are set: TP sensor, VSS, ECT,
EGR, fuel system, MAF, MAP, IAT, canister purge,
injector control or ignition control.

Barometric pressure is above 75 kPa.

Engine coolant temperature is above 50
C (120
F).

Engine speed is more than 100-200 RPM lower than
desired idle, based upon coolant temperature.

The engine has been running for at least 125 seconds.

Vehicle speed is less than 1 mph.

Canister purge duty cycle is above 10%.

Ignition voltage is between 9.5 volts and 16.7 volts.

Engine speed is lower than desired idle.
All of the above conditions are met for 5 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

DTC P1509 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 or IAC motor ± 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 for damage.

Vacuum leak ± Check for a condition that causes a
vacuum leak, such as disconnected or damaged
hoses, leaks at the EGR valve and the EGR pipe to the
intake manifold, leaks at the throttle body, faulty or
incorrectly installed PCV valve, leaks at the intake
manifold, etc.

6E±262
ENGINE DRIVEABILITY AND EMISSIONS
Symptom Diagnosis
Preliminary Checks
Before using this section, perform the ªOn-Board
Diagnostic (OBD) System Checkº and verify all of the
following items:

The powertrain control module (PCM) and malfunction
indicator lamp (MIL) (Service Engine Soon lamp) are
operating correctly.

There are no DTC(s) stored.

Tech 2 data is within normal operating range. Refer to
Typical Scan Data Values.

Verify the customer complaint and locate the correct
symptom in the table of contents. Perform the
procedure included in the symptom chart.
Visual/Physical Check
Several of the symptom procedures call for a careful
visual/physical check. This can lead to correcting a
problem without further checks and can save valuable
time.
This check should include the following items:

PCM grounds for cleanliness, tightness and proper
location.

Vacuum hoses for splits, kinks, and proper
connections, as shown on the ªVehicle Emission
Control Informationº label. Check thoroughly for any
type of leak or restriction.

Air intake ducts for collapsed or damaged areas.

Air leaks at throttle body mounting area, mass air flow
(MAF) sensor and intake manifold sealing surfaces.

Ignition wires for cracking, hardness, and carbon
tracking.

Wiring for proper connections, pinches and cuts.
Intermittents
IMPORTANT:An intermittent problem may or may not
turn on the malfunction indicator lamp (MIL) or store a
DTC. DO NOT use the Diagnostic Trouble Code (DTC)
charts for intermittent problems. The fault must be
present to locate the problem.
Most intermittent problems are caused by faulty electrical
connections or wiring. Perform a careful visual/physical
check for the following conditions:

Poor mating of the connector halves or a terminal not
fully seated in the connector (backed out).

Improperly formed or damaged terminal.

All connector terminals in the problem circuit should be
carefully checked for proper contact tension.

Poor terminal-to-wire connection. This requires
removing the terminal from the connector body to
check.
Road test the vehicle with a J 39200 Digital Multimeter
connected to a suspected circuit. An abnormal voltage
when the malfunction occurs is a good indication that
there is a fault in the circuit being monitored.
Use Tech 2 to help detect intermittent conditions. Tech 2s
have several features that can be used to locate anintermittent condition. Use the following feature to find
intermittent faults:

Using Tech 2's ªFreeze Frameº buffer or ªFailure
Recordsº buffer can aid in locating an intermittent
condition. Review and record the information in the
freeze frame or failure record associated with the
intermittent DTC being diagnosed. The vehicle can be
driven within the conditions that were present when the
DTC originally set.
To check for loss of diagnostic code memory, disconnect
the MAP sensor and idle the engine until the MIL (Service
Engine Soon lamp) comes on. DTC P0107 should be
stored and kept in memory when the ignition is turned
ªOFF.º If not, the PCM is faulty. When this test is
completed, make sure that you clear the DTC P0107 from
memory.
An intermittent MIL (Service Engine Soon lamp) with no
stored DTC may be caused by the following:

Ignition coil shorted to ground and arcing at ignition
wires or plugs.

MIL (Service Engine Soon lamp) wire to PCM shorted
to ground.

Poor PCM grounds. Refer to the PCM wiring
diagrams.
Check for improper installation of electrical options such
as lights, cellular phones, etc. Route ignition coil wiring
away from the ignition coils. Check all wires from the
PCM to the ignition coil for poor connections.
Check for an open diode across the A/C compressor
clutch and check for other open diodes (refer to wiring
diagrams in
Electrical Diagnosis).
If problem has not been found, refer to
PCM Connector
Symptom
tables.

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