ENGINE CONTROL SYSTEM
EC-23
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EC
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all four cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The four fuel injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
FUEL SHUT-OFF
Fuel to each cylinder is cut off during deceleration or operation of the engine at excessively high speeds.
Electronic Ignition (EI) SystemBBS005BG
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
Firing order: 1-3-4-2
The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of the
engine. The ignition timing data is stored in the ECM.
The ECM receives information such as the injection pulse width and camshaft position sensor signal. Comput-
ing this information, ignition signals are transmitted to the power transistor.
During the following conditions, the ignition timing is revised by the ECM according to the other data stored in
the ECM.
At starting
During warm-up
At idle
At low battery voltage
During acceleration
SEF337W
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
2
Piston position
Ignition timing
controlPower transistor Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery
Battery voltage*
2
Wheel sensor
Vehicle speed*1
EC-360
[VQ]
ENGINE CONTROL SYSTEM
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all six cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The six fuel injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
FUEL SHUT-OFF
Fuel to each cylinder is cut off during deceleration, operation of the engine at excessively high speeds or oper-
ation of the vehicle at excessively high speed.
Electronic Ignition (EI) SystemBBS004XK
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
Firing order: 1 - 2 - 3 - 4 - 5 - 6
The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of the
engine. The ignition timing data is stored in the ECM.
The ECM receives information such as the injection pulse width and camshaft position sensor signal. Comput-
ing this information, ignition signals are transmitted to the power transistor.
During the following conditions, the ignition timing is revised by the ECM according to the other data stored in
the ECM.
At starting
During warm-up
At idle
At low battery voltage
SEF179U
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
2
Piston position
Ignition timing
controlPower transistor Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery
Battery voltage*
2
Wheel sensor
Vehicle speed*1
EC-688
[VQ]
FUEL INJECTOR
6. CHECK FUNCTION OF FUEL INJECTOR-III
1. Reconnect all harness connector disconnected.
2. Start engine.
3. Listen to fuel injectors No. 2, No. 4, No.6 operating sound.
OK or NG
OK >>INSPECTION END
NG >> GO TO 7.
7. CHECK FUEL INJECTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect fuel injector harness connector.
3. Turn ignition switch ON.
4. Check voltage between fuel injector terminal 1 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.
Harness connectors M52, F103
Harness connectors F1, F251
Fuse block (J/B) connector M1
10A fuse
Harness for open or short between fuel injector and fuse
>> Repair harness or connectors. Clicking noise should exist.
PBIB1986E
Voltage: Battery voltage
PBIB2182E
PBIB0582E
FUEL INJECTOR AND FUEL TUBE
EM-37
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2. Install fuel injector to fuel tube with the following procedure:
a. Insert clip into clip mounting groove on fuel injector.
Insert clip so that protrusion “A” of fuel injector matches cutout
“A” of clip.
CAUTION:
Do not reuse clip. Replace it with a new one.
Be careful to keep clip from interfering with O-ring. If
interference occurs, replace O-ring.
b. Insert fuel injector into fuel tube with clip attached.
Insert it while matching it to the axial center.
Insert fuel injector so that protrusion “B” of fuel tube matches
cutout “B” of clip.
Make sure that fuel tube flange is securely fixed in flange fix-
ing groove on clip.
c. Make sure that installation is complete by checking that fuel
injector does not rotate or come off.
Make sure that protrusions of fuel injectors are aligned with
cutouts of clips after installation.
3. From the engine rear side, set fuel tube and fuel injector assembly at its position for installation on intake
manifold.
CAUTION:
When installing, be careful to avoid any interference with fuel injector.
4. Set fuel tube protector onto fuel tube.
5. Tighten mounting bolts with the following procedure.
Tighten bolts evenly in two steps in numerical order as shown
in the figure.
6. Connect sub-harness for fuel injector.
7. Note the following, and connect quick connectors at engine side and vehicle side to install fuel feed hose.
NOTE:
There is quick connector for the engine side and for the vehicle side, and they have different shapes. But
connection is same procedure. The following procedure shows the engine side.
a. Check the connection for foreign material and damage.
b. Align center to insert quick connector straightly into fuel tube.
Insert quick connector to fuel tube until the top spool on fuel
tube is inserted completely and the second level spool is posi-
tioned slightly below quick connector bottom end.
CAUTION:
Hold “A” position in the figure when inserting fuel tube
into quick connector.
Carefully align center to avoid inclined insertion to pre-
vent damage to O-ring inside quick connector.
PBIC2651E
1st step
: 10.1 N·m (1.0 kg-m, 7 ft-lb)
2nd step
: 23.6 N·m (2.4 kg-m, 17 ft-lb)
PBIC2180E
KBIA0272E
EM-158
[VQ]
FUEL INJECTOR AND FUEL TUBE
CAUTION:
Upper and lower O-rings are different. Be careful not to confuse them.
Handle O-ring with bare hands. Do not wear gloves.
Lubricate O-ring with new engine oil.
Do not clean O-ring with solvent.
Make sure that O-ring and its mating part are free of foreign material.
When installing O-ring, be careful not to scratch it with tool or fingernails. Also be careful not to
twist or stretch O-ring. If O-ring was stretched while it was being attached, do not insert it
quickly into fuel tube.
Insert O-ring straight into fuel injector. Do not decenter or twist it.
3. Install fuel injector to fuel tube as follows:
a. Insert clip into clip mounting groove on fuel injector.
Insert clip so that protrusion “A” of fuel injector matches cut-
out“A” of clip.
CAUTION:
Do not reuse clip. Replace it with new one.
Be careful to keep clip from interfering with O-ring. If
interference occurs, replace O-ring.
b. Insert fuel injector into fuel tube with clip attached.
Insert it while matching it to the axial center.
Insert fuel injector so that protrusion “B” of fuel tube matches
cutout “B” of clip.
Make sure that fuel tube flange is securely fixed in flange fix-
ing groove on clip.
c. Make sure that installation is complete by checking that fuel
injector does not rotate or come off.
Make sure that protrusions of fuel injectors are aligned with
cutouts of clips after installation.
4. Install spacers on intake manifold.
5. Install fuel tube and fuel injector assembly to intake manifold
CAUTION:
Be careful not to let tip of injector nozzle come in contact with other parts.
Tighten mounting bolts in two steps in numerical order as
shown in the figure.Fuel tube side
VQ23DE : Black
VQ35DE : Blue
Nozzle side
VQ23DE : Green
VQ35DE : Brown
PBIC2545E
1st step
: 10.1 N·m (1.0 kg-m, 7 ft-lb)
2nd step
: 23.6 N·m (2.4 kg-m, 17 ft-lb)
SEC999C
GI-6
PRECAUTIONS
WARNING:
To prevent ECM from storing the diagnostic trouble codes, do not carelessly disconnect the harness
connectors which are related to the engine control system and TCM (transmission control module)
system. The connectors should be disconnected only when working according to the WORK FLOW of
TROUBLE DIAGNOSES in EC and AT sections.
Precautions for Three Way CatalystBAS00074
If a large amount of unburned fuel flows into the catalyst, the catalyst temperature will be excessively high. To
prevent this, follow the instructions.
Use unleaded gasoline only. Leaded gasoline will seriously damage the three way catalyst.
When checking for ignition spark or measuring engine compression, make tests quickly and only when
necessary.
Do not run engine when the fuel tank level is low, otherwise the engine may misfire, causing damage to
the catalyst.
Do not place the vehicle on flammable material. Keep flammable material off the exhaust pipe and the three
way catalyst.
Precautions for FuelBAS0008E
QR20DE/VQ23DE ENGINE (REGULAR GASOLINE, UNLEADED PREMIUM GASOLINE RECOM-
MENDED)
Use unleaded regular gasoline with an octane rating of at least 91 RON (research octane number).
CAUTION:
Do not use leaded gasoline. Using leaded gasoline will damage the three way catalyst. Using a fuel
other than that specified could adversely affect the emission control devices and systems, and could
also affect the warranty coverage validity.
VQ35DE ENGINE (PREMIUM GASOLINE)
Use unleaded premium gasoline with an octane rating of at least 95 RON (research octane number).
If unleaded premium gasoline is not available, unleaded regular gasoline with an octane rating of at least 91
RON (research octane number) can be used, but only under the following precautions:
have the fuel tank filled only partially with unleaded regular gasoline, and fill up with unleaded premium
gasoline as soon as possible.
avoid full throttle driving and abrupt acceleration.
However, for maximum vehicle performance, the use of unleaded premium gasoline is recommended.
CAUTION:
Do not use leaded gasoline. Using leaded gasoline will damage the three way catalyst. Using a fuel
other than that specified could adversely affect the emission control devices and systems, and could
also affect the warranty coverage validity.
Precautions for Multiport Fuel Injection System or Engine Control SystemBAS0008F
Before connecting or disconnecting any harness connector for
the multiport fuel injection system or ECM:
Turn ignition switch to “OFF” position.
Disconnect negative battery terminal.
Otherwise, there may be damage to ECM.
Before disconnecting pressurized fuel line from fuel pump to
injectors, be sure to release fuel pressure.
Be careful not to jar components such as ECM and mass air
flow sensor.
SGI787