engine coolant ISUZU TF SERIES 2004 Owners Manual
[x] Cancel search | Manufacturer: ISUZU, Model Year: 2004, Model line: TF SERIES, Model: ISUZU TF SERIES 2004Pages: 4264, PDF Size: 72.63 MB
Page 2050 of 4264
6E-54 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Crankshaft Position (CKP) Sensor
The crankshaft position (CKP) sensor, which sends a
signal necessary for deciding on injection timing to the
ECM, is mounted on the right-hand side of the cylinde
r
block.
The crankshaft has a 58 teeth press-fit timing disc, from
which the CKP sensor reads the position of the
crankshaft at all the times. It converts this to an
electrical signal, which it sends to the ECM.
Of the 58 teeth, 57 have a base with of 3°, and are
evenly spaced, but tooth No. 58 is 15° wide at its based
to serve as a timing mark, allowing the sensor to repor
t
the standard crankshaft position.
Using the 58 X signals per rotation and the timing-mark
signal sent by the CKP sensor, the ECM is able to
accurately calculate engine speed and crank position.
Also, the position of each cylinder is precisely known by
the ECM from signals sent by the camshaft position
(CMP) sensor, so the sequential multi-point fuel
injection can be controlled with accuracy.
The 58 X signals are converted by the ECM into a
retangle wave signal. This converted signal is sent from
the ECM terminal B12 to the tachometer and transfe
r
case control module (TCCM) terminal 15 (if 4WD
model).
Engine Coolant Temperature (ECT) Sensor
The ECT sensor is a thermistor. A temperature
changes the resistance value. And it changes voltage.
In other words it measures a temperature value. It is
installed on the coolant stream. Low coolan
t
temperature produces a high resistance.
The ECM supplies 5 volts signal to the ECT senso
r
through resisters in the ECM and measures the voltage.
The signal voltage will be high when the engine
temperature is cold, and it will be low when the engine
temperature is hot.
Characteris tic of ECT Sens or
10 100 1000 10000 100000-3010 50 90130Temperature (
)
Resistance (Ω)
Page 2053 of 4264
3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-57
Starting Mode
When the ignition is first turned "ON," the ECM
energizes the fuel pump relay for two seconds to allo
w
the fuel pump to build up pressure. The ECM then
checks the engine coolant temperature (ECT) senso
r
and the throttle position sensor to determine the proper
air/fuel ratio for starting.
The ECM controls the amount of fuel delivered in the
starting mode by adjusting how long the fuel injectors
are energized by pulsing the injectors for very short
times.
Fuel Metering System Components
The fuel metering system is made up of the following
parts.
Fuel injector
Throttle Body
Fuel Rail
Fuel Pressure regulator
ECM
Crankshaft position (CKP) sensor
Camshaft position (CMP) sensor
Idle air control valve
Fuel pump
Fuel Injector
The sequential multi-port fuel injection fuel injector is a
solenoid operated device controlled by the ECM. The
ECM 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.
Fuel Pressure Regulator
The fuel pressure regulator is a diaphragm-operated
relief valve mounted on the fuel rail with fuel pump
pressure on one side and manifold pressure on the
other side. The fuel pressure regulator maintains the
fuel pressure available to the injector at three times
barometric pressure adjusted for engine load. It may be
serviced separate.
If the pressure is too low, poor performance and a DTC
P0131, P0151, P0171, P0174, P1171 or P1174 will be
the result. If the pressure is too high, excessive odo
r
and/or a DTC P0132, P0152, P0172 or P0175 will be
the result. Refer to Fuel System Diagnosisfo
r
information on diagnosing fuel pressure conditions.
Fuel Rail
The fuel rail is mounted to the top of the engine and
distributes fuel to the individual injectors. Fuel is
delivered to the fuel inlet tube of the fuel rail by the fuel
lines. The fuel goes through the fuel rail to the fuel
pressure regulator. The fuel pressure regulato
r
maintains a constant fuel pressure at the injectors.
Remaining fuel is then returned to the fuel tank.
055RV009
Fuel Pump Electrical Circuit
When the key is first turned "ON," the ECM energizes
the fuel pump relay for two seconds to build up the fuel
pressure quickly. If the engine is not started within two
seconds, the ECM shuts the fuel pump off and waits
until the engine is cranked. When the engine is cranked
and the 58 X crankshaft position signal has been
detected by the ECM, the ECM supplies 12 volts to the
fuel pump relay to energize the electric in-tank fuel
pump.
An inoperative fuel pump will cause a "no-start"
condition. A fuel pump which does not provide enough
pressure will result in poor performance.
Camshaft Position (CMP) Sensor Signal
The ECM uses this signal to determine the position o
f
the number 1 piston during its power stroke, allowing
the ECM to calculate true sequential multiport fuel
injection. Loss of this signal will set a DTC P0341. If the
CMP signal is lost while the engine is running, the fuel
injection system will shift to a calculated sequential fuel
injection based on the last fuel injection pulse, and the
engine will continue to run. The engine can be restarted
and will run in the calculated sequential mode as long
as the fault is present, with a 1-in-6 chance of being
correct.
Page 2054 of 4264
6E-58 3.5L ENGINE DRIVEABILITY AND EMISSIONS
GENERAL DESCRIPTION FOR
ELECTRONIC IGNITION SYSTEM IGNITION
COILS & CONTROL
A separate coil-at-plug module is located at each spark
plug.
The coil-at-plug module is attached to the engine with
two screws. It is installed directly to the spark plug by an
electrical contact inside a rubber boot.
A three way connector provides 12 volts primary supply
from the ignition coil fuse, a ground switching trigge
r
line from the ECM, and ground.
The ignition control spark timing is the ECM's method o
f
controlling the spark advance and the ignition dwell.
The ignition control spark advance and the ignition dwell
are calculated by the ECM using the following inputs.
Engine speed
Crankshaft position (CKP) sensor
Camshaft position (CMP) sensor
Engine coolant temperature (ECT) sensor
Throttle position sensor
Park or neutral position switch
Vehicle speed sensor
ECM and ignition system supply voltage
Based on these sensor signal and engine load
information, the ECM sends 5V to each ignition coil
requiring ignition. This signal sets in the powe
r
transistor of the ignition coil to establish a grounding
circuit for the primary coil, applying battery voltage to
the primary coil.
At the ignition timing, the ECM stops sending the 5V
signal voltage. Under this condition the power transistor
of the ignition coil is set off to cut the battery voltage to
the primary coil, thereby causing a magnetic field
generated in the primary coil to collapse.
On this moment a line of magnetic force flows to the
secondary coil, and when this magnetic line crosses the
coil, high voltage induced by the secondary ignition
circuit to flow through the spark plug to the ground.
Ignition Control ECM Output
The ECM 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 ("coil-at-plug") located at the
spark plug itself. When the ignition coil receives the
5-volt signal from the ECM, it provides a ground path fo
r
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
ECM 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 ECM and the ignition coil is
monitored for open circuits, shorts to voltage, and
shorts to ground. If the ECM 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
Spark Plug
Although worn or dirty spark plugs may give satisfactory
operation at idling speed, they frequency fail at highe
r
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 wea
r
will also occur. Engines which are not running properly
are often referred to as “misfiring." This means the
ignition spark is not igniting the air/fuel mixture at the
proper time.
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.
Page 2057 of 4264
3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-61
GENERAL DESCRIPTION FOR
EVAPORATIVE EMISSION SYSTEM
3 1 2
(1) Purge Solenoid Valve
(2) From Canistor to Purge Solenoid
(3) From Purge Solenoid to Intake
1
2
(1) Canistor
(2) Air Separator
The basic evaporative emission control system used on
the charcoal canister storage method. The method
transfers fuel vapor from the fuel tank to an activated
carbon (charcoal) storage devise to hold the vapors
when the vehicle is not operating.
The canister is located on the rear axle housing by the
frame cross-member.
When the engine is running, the fuel vapor is purged
from the carbon element by intake air flow and
consumed in the normal combustion process.
EVAP Control System
The evaporate emission canister purge is controlled by
a duty solenoid valve that allows manifold to purge the
canister when following operating conditions are met.
Purge solenoid valve operating condition at idle
condition:
Engine speed is below 1000rpm.
Vehicle speed is below 3km/h.
Engine coolant temperature is more than 80C.
Intake air temperature is more than 10C.
In closed loop operation.
All above conditions are met for 4 seconds.
Purge solenoid valve operating condition at other than
idle condition:
Engine speed is below 6375rpm.
Vehicle speed is more than 14km/h.
Engine coolant temperature is more than 60C.
All above conditions are met for 4 seconds.
Results of Incorrect Operation
Poor idle, stalling and poor driveability can be caused
by:
Inoperative purge solenoid.
Damaged canister.
Hoses split, cracked and/or not connected to the
proper tubes.
Evidence of fuel loss or fuel vapor odor can be caused
by:
Liquid fuel leaking from fuel lines, or fuel pump.
Cracked or damaged canister.
Disconnected, misrouted, kinked, deteriorated o
r
damaged vapor hoses, or control hoses.
If the solenoid is always open, the canister can purge to
the intake manifold at all times. This can allow extra fuel
at idle or during warm-up, which can cause rough o
r
unstable idle, or too rich operation.
If the solenoid is always closed, the canister can
become over-loaded, resulting in fuel odor.
Page 2058 of 4264
6E-62 3.5L ENGINE DRIVEABILITY AND EMISSIONS
GENERAL DESCRIPTION FOR EXHAUST
GAS RECIRCULATION (EGR) SYSTEM
Linear EGR Valve
060R200237
Legend
(1) ECM
(2) Linear EGR Valve
(3) Throttle
(4) Exhaust Manifold
The exhaust gas re-circulation (EGR) system is used to
reduce emission levels of oxides of nitrogen (NOx).
NOx emission levels are caused by a high combustion
levels by decreasing the combustion temperature.
The EGR valve feeds small amount of exhaust gas
back into the combustion chamber. The fuel/air mixture
will be diluted and combustion temperatures reduced.
Linear EGR valve Operation and Results o
f
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 exhaus
t
to the intake manifold through an orifice with a ECM
controlled pintle. During operation, the ECM controls
pintle position by monitoring the pintle position feedback
signal.
The linear EGR valve is activated under the following
conditions:
No DTC relating to the EGR.
Engine speed is between 1200 and 4375rpm.
Engine coolant temperature is between 20 and
100.
Throttle position sensor output voltage is belo
w
3V.
Too mach EGR flow at idle, cruise or cold operation
may cause any of the following conditions to occur:
Engine stalls after a cold start.
Engine stalls at idle after deceleration.
Vehicle surges during cruise.
Rough idle.
Too little or no EGR flow may allow combustion
temperatures to get too high. This could cause:
Spark knock (detonation).
Emission test failure.
Poor fuel economy.
Page 2067 of 4264
3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-71
Basic Knowledge of Tools Required
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
effectively use this section of the Service Manual.
Serial Data Communications
Class II Serial Data Communications
This vehicle utilizes the “Class II" communication
system. Each bit of information can have one of two
lengths: long or 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. The most significant result of this regulation
is that it provides Tech 2 manufacturers with the
capability to access data from any make or model
vehicle that is sold.
The data displayed on the other Tech 2 will appear the
same, with some exceptions. Some scan tools will only
be able to display certain vehicle parameters as values
that are a coded representation of the true or actual
value. For more information on this system of coding,
refer to Decimal/Binary/Hexadecimal Conversions.On
this vehicle the Tech 2 displays the actual values fo
r
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 curren
t
ignition cycle.
The fault identified by the diagnostic test is no
t
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.
Remember, a fuel trim DTC may be triggered by a list o
f
vehicle faults. Make use of all information available
(other DTCs stored, rich or lean condition, etc.) when
diagnosing a fuel trim fault.
Comprehensive Component Monitor
Diagnostic Operation
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, i.e.throttle position sensor that indicates
high throttle position at low engine loads. Inpu
t
components may include, but are not limited to the
following sensors:
Vehicle Speed Sensor (VSS)
Inlet Air Temperature (IAT) Sensor
Crankshaft Position (CKP) Sensor
Throttle Position Sensor (TPS)
Engine Coolant Temperature (ECT) Sensor
Camshaft Position (CMP) Sensor
Mass Air Flow (MAF) Sensor
In addition to the circuit continuity and rationality check
the ECT sensor is monitored for its ability to achieve a
steady state temperature to enable closed loop fuel
control.
Output Components:
Output components are diagnosed for proper response
to control module commands. Components where
functional monitoring is not feasible will be monitored fo
r
circuit continuity and out-of-range values if applicable.
Output components to be monitored include, but are no
t
limited to, the following circuit:
Idle Air Control (IAC) Valve
Control module controlled EVAP Canister Purge
Valve
Electronic Transmission controls
A/C relays
VSS output
MIL control
Refer to ECM and Sensors in General Descriptions.
Page 2075 of 4264
3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-79
TYPICAL SCAN DATA & DEFINITIONS (ENGINE DATA)
Use the typical values table only after the On-Board Diagnostic System check has been completed, no DTC(s) were noted, and you have determined that the On-Board
Diagnostic are functioning properly.
Tech2 values from a properly running engine may be used for comparison with the engine you are diagnosing.
Condition : Vehicle stopping, engine running, air conditioning off & after warm-up (Coolant temperature approximately 80C)
Tech 2
Parameter
Units Idle 2000rpm Definitions
1 Ignition Voltage V 10.0 14.5 10.0 14.5 This displays the system voltage measured by the ECM at ignition feed.
2 Engine Speed rpm 710 860 1950 2050 The actual engine speed is measured by ECM from the CKP sensor 58X signal.
3 Desired Idle
Speed rpm 750 770 750 770 The desired engine idle speed that the ECM commanding.
The ECM compensates for various engine loads.
4 Engine Coolant
Temperature C or F 80 90 () 80 90 () The ECT is measured by ECM from ECT sensor output voltage.
When the engine is normally warm upped, this data displays approximately 80 °C or
more.
5 Start Up ECT
(Engine Coolant
Temperature) C or F Depends on ECT
at start-up
Depends on ECT
at start-up
Start-up ECT is measured by ECM from ECT sensor output voltage when engine is
started.
6 Intake Air
Temperature
C or F Depends on
ambient temp.
Depends on
ambient temp.
The IAT is measured by ECM from IAT sensor output voltage.
This data is changing by intake air temperature.
7 Throttle Position % 0 4 6 Throttle position operating angle is measured by the ECM from throttle position
output voltage.
This should display 0% at idle and 99 100% at full throttle.
8 Throttle Position
Sensor V 0.4 0.7 0.6 0.8 The TPS output voltage is displayed.
This data is changing by accelerator operating angle.
9 Mass Air Flow g/s 5.0 8.0 13.0 16.0 This displays intake air amount.
The mass air flow is measured by ECM from the MAF sensor output voltage.
10 Air Fuel Ratio 14.7:1 14.7:1 This displays the ECM commanded value.
In closed loop, this should normally be displayed around 14.2:1 14.7:1.
11 Idle Air Control Steps 10 20 20 30 This displays the ECM commanded position of the idle air control valve pintle.
A larger number means that more air is being commanded through the idle air
passage.
12 EGR Valve V 0.00 0.00 0.10 The EGR position sensor output voltage is displayed.
This data is changing by EGR valve solenoid operating position.
13 Desired EGR
Opening V 0.00 0.05 1.10 The ECM commanded EGR position sensor voltage is displayed.
According to the current position, ECM changes EGR valve solenoid operating
position to meet the desired position.
14 EGR Valve On
Duty % 0 32 – 38 This displays the duty signal from the ECM to control the EGR valve.
15 Engine Load % 2 7 8 15 This displays is calculated by the ECM form engine speed and MAF sensor reading.
Engine load should increase with an increase in engine speed or air flow amount.
16 B1 Fuel System
Status Open Loop/ Close
Loop Close Loop Close Loop
17 B2 Fuel System
Status Open Loop/ Close
Loop Close Loop Close Loop
When the engine is first started the system is in "Open Loop" operation.
In "Open Loop", the ECM ignores the signal from the oxygen sensors.
When various conditions (ECT, time from start, engine speed & oxygen sensor
output) are met, the system enters "Closed Loop" operation.
In "Closed Loop", the ECM calculates the air fuel ratio based on the signal from the
oxygen sensors.
18 Fuel Trim
Learned (Bank 1) Yes/No Yes Yes
19 Fuel Trim
Learned (Bank 2) Yes/No Yes Yes
When conditions are appropriate for enabling long term fuel trim corrections, fuel trim
learn will display "Yes".
This indicates that the long term fuel trim is responding to the short term fuel trim.
If the fuel trim lean displays "No", then long term fuel trim will not respond to changes
in short term fuel trim.
20 Injection Pulse
Bank 1 ms 2.0 4.0 2.0 4.0
21 Injection Pulse
Bank 2 ms 2.0 4.0 2.0 4.0
This displays the amount of time the ECM is commanding each injector On 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.
22 Spark Advance °CA 10 15 35 42 This displays the amount of spark advance being commanded by the ECM.
Page 2077 of 4264
3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-81
TYPICAL SCAN DATA & DEFINITIONS (O2 SENSOR DATA)
Use the typical values table only after the On-Board Diagnostic System check has been completed, no DTC(s) were noted, and you have determined that the On-Board
Diagnostic are functioning properly.
Tech2 values from a properly running engine may be used for comparison with the engine you are diagnosing.
Condition : Vehicle stopping, engine running, air conditioning off & after warm-up (Coolant temperature approximately 80 C)
Tech 2
Parameter
Units Idle 2000rpm Definitions
1 Ignition Voltage V 10.0 14.5 10.0 14.5 This displays the system voltage measured by the ECM at ignition feed.
2 Engine Speed rpm 710 860 1950 2050 The actual engine speed is measured by ECM from the CKP sensor 58X signal.
3 Desired Idle
Speed rpm 750 770 750 770 The desired engine idle speed that the ECM commanding.
The ECM compensates for various engine loads.
4 Engine Coolant
Temperature C or F 80 90 (C) 80 90 (C) The ECT is measured by ECM from ECT sensor output voltage.
When the engine is normally warm upped, this data displays approximately 80 °C or
more.
5 Start Up ECT
(Engine Coolant
Temperature) C or F Depends on ECT
at start-up
Depends on ECT
at start-up
Start-up ECT is measured by ECM from ECT sensor output voltage when engine is
started.
6 Throttle Position % 0 4 6 Throttle position operating angle is measured by the ECM from throttle position
output voltage.
This should display 0% at idle and 99 100% at full throttle.
7 Throttle Position
Sensor V 0.4 0.7 0.6 0.8 The TPS output voltage is displayed.
This data is changing by accelerator operating angle.
8 Mass Air Flow g/s 5.0 8.0 13.0 16.0 This displays intake air amount.
The mass air flow is measured by ECM from the MAF sensor output voltage.
9 Air Fuel Ratio 14.7:1 14.7:1 This displays the ECM commanded value. In closed loop, this should normally be
displayed around 14.2:1 14.7:1.
10 Engine Load % 2 7 8 15 This displays is calculated by the ECM form engine speed and MAF sensor reading.
Engine load should increase with an increase in engine speed or air flow amount.
11 B1 Fuel System
Status Open Loop/ Close
Loop Close Loop Close Loop
12 B2 Fuel System
Status Open Loop/ Close
Loop Close Loop Close Loop
When the engine is first started the system is in "Open Loop" operation.
In "Open Loop", the ECM ignores the signal from the oxygen sensors.
When various conditions (ECT, time from start, engine speed & oxygen sensor
output) are met, the system enters "Closed Loop" operation.
In "Closed Loop", the ECM calculates the air fuel ratio based on the signal from the
oxygen sensors.
13 B1S1 O2 Sensor
(Bank1 Sensor 1)
mV 50 950 50 950
14 B2S1 O2 Sensor
(Bank2 Sensor 1)
mV 50 950 50 950
This displays the exhaust oxygen sensor output voltage.
Should fluctuate constantly within a range between 10mV (lean exhaust) and
1000mV (rich exhaust) while operating in closed loop.
15 B1 O2 Sensor
Ready (Bank 1)
Yes/No Yes Yes
16 B2 O2 Sensor
Ready (Bank 2)
Yes/No Yes Yes
This displays the status of the exhaust oxygen sensor.
This display will indicate "Yes" when the ECM detects a fluctuating oxygen sensor
output voltage sufficient to allow closed loop operation.
This will not occur unless the oxygen sensor is warmed up.
17 B1 Long Term
Fuel Trim (Bank
1)
% -10 20 -10 20
18 B2 Long Term
Fuel Trim (Bank
2)
% -10 20 -10 20
The long term fuel trim is delivered from the short term fuel term values and
represents a long term correction of fuel delivery for bank in question.
A value of 0% indicates that fuel delivery requires no compensation to maintain the
ECM commanded air fuel ratio.
A negative value indicates that the fuel system is rich and fuel delivery is being
reduced (decreased injector pulse width).
A positive value indicates that a lean condition exists and the ECM is compensating
by add 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.
Excessive long term fuel trim values may indicate an rich or lean condition.
Page 2079 of 4264
3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E -83
MISCELLANEOUS TEST
The state of each circuit can be tested by using
miscellaneous test menus. Especially when DTC cannot
be detected, a faulty circuit can be diagnosed by testing
each circuit by means of these menus.
Even DTC has been detected, the circuit tests using
these menus could help discriminate between a
mechanical trouble and an electrical trouble.
Connect Tech 2 and select "Powertrain", "3.5L V6 6VE1
Hitachi" & "Miscellaneous Test".
F0: Lamps
F0: Malfunction Indicator Lamp
When the Tech 2 is operated, "Malfunction Indicato
r
Lamp (Check Engine Lamp)" is turned on or off.
The circuit is normal if the "Malfunction Indicator Lamp
(Check Engine Lamp)" in the instrument panel is turned
on or off in accordance with this operation.
F1: Relays
F0: Fuel Pump Relay
When the Tech 2 is operated, fuel pump relay signal
turns ON or OFF.
The circuit is normal if fuel pump sound is generated in
accordance with this operation when key switch is
turned ON.
"F1: A/C Clutch Relay"
When the Tech 2 is operated, A/C clutch relay signal
turns ON or OFF.
The circuit is normal if A/C compressor clutch is
energized in accordance with this operation when the
engine is running.
F2: EVAP
F0: Purge Solenoid
When the Tech 2 is operated, duty ratio of EVAP purge
solenoid is changed 10%-by-10%.
Purge Solenoid
Engine Speed 800 RPM
Desired Idle Speed 762 RPM
Engine Coolant Temperature 80
C
Start Up ECT 50
C
Intake Air Temperature 30
C
Throttle Position 0 %
EVAP Purge Solenoid 10 %
Press "Increase" key.
Then, EVAP Purge Solenoid increases
10%-by-10%.
Press "Quit" Key.
F3: IAC System
F0: RPM Control
When the Tech 2 is operated, "Desired Idle Speed"
increases 50rpm-by-50rpm up to 1550rpm.
The circuit is normal if engine speed is changed in
accordance with this operation.
RPM Control
Engine Speed 850 RPM
Desired Idle Speed 850 RPM
Engine Coolant Temperature 80
C
Start Up ECT 50
C
Intake Air Temperature 30
C
Throttle Position 0 %
Desired Idle Speed 850 RPM
Press "Increase" key.
Then, Desired Idle speed increases
50rpm-by-50rpm up to 1550rpm. Engine speed is
also changed by this operation.
Press "Quit" Key.
F0: IAC Control
When the Tech 2 is operated, "Idle Air Control"
increases or decreases 10steps-by-10steps up to
160steps.
The circuit is normal if idle engine speed is changed in
accordance with this operation.
IAC Control
Engine Speed 875 RPM
Desired Idle Speed 762 RPM
Engine Coolant Temperature 80
Start Up ECT 50
Intake Air Temperature 30
Throttle Position 0 %
Idle Air Control 30 Steps
Press "Increase" key.
Then, Idle Air Control increases 10steps-by-
10steps up to 160steps.
Engine speed is also changed by this operation.
Press "Quit" Key.
Page 2104 of 4264
6E-108 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Injector Coil Test Procedure (Steps 1-6) and Injector Balance Test Procedure
(Steps 7-11)
Step Action Value(s) YES NO
1
Was the “On-Board Diagnostic (OBD) System Check"
performed?
— Go to Step 2 Go to OBD
System Check
2 1. Turn the engine “OFF."
In order to prevent flooding of a single cylinder and
possible engine damage, relieve the fuel pressure
before performing the fuel injector coil test procedure.
2. Relieve the fuel pressure. Refer to Test
Description Number 2.
3. Connect the 5–8840–2618–0 Fuel Injector Tester
to B+ and ground, and to the 5–8840–2635–0
Injector Switch Box.
4. Connect the injector switch box to the gray fuel
injector harness connector located at the rear of
the air cleaner assembly.
5. Set the amperage supply selector switch on the
fuel injector tester to the “Coil Test" 0.5 amp
position.
6. Connect the leads from the Digital Voltmeter
(DVM) to the injector tester. Refer to the
illustrations associated with the test description.
7. Set the DVM to the tenths scale (0.0).
8. Observe the engine coolant temperature.
Is the engine coolant temperature within the specified
values? 10C (50F) to
35C (95F) Go to Step 3 Go to Step 5
3
1. Set injector switch box injector #1.
2. Press the “Push to Start Test" button on the fuel
injector tester.
3. Observe the voltage reading on the DVM.
Important: The voltage reading may rise during the
test.
4. Record the lowest voltage observed after the first
second of the test.
5. Set the injector switch box to the next injector and
repeat steps 2, 3, and 4.
Did any fuel injector have an erratic voltage reading
(large fluctuations in voltage that did not stabilize) or a
voltage reading outside of the specified values? 5.7-6.6 V Go to Step 4 Go to Step 7
4 Replace the faulty fuel injector(s). Refer to Fuel
Injector.
Is the action complete? — Go to Step 7 —