VIAS
EC-457
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VIASPFP:14956
DescriptionEBS011HT
SYSTEM DESCRIPTION
*: The ECM determines the start signal status by the signals of engine speed and battery voltage.
When the engine is running at low or medium speed, the power valve is fully closed. Under this condition, the
effective suction port length is equivalent to the total length of the intake manifold collector's suction port
including the intake valve. This long suction port provides increased air intake which results in improved suc-
tion efficiency and higher torque generation.
The surge tank and one-way valve are provided. When engine is running at high speed, the ECM sends the
signal to the VIAS control solenoid valve. This signal introduces the intake manifold vacuum into the power
valve actuator and therefore opens the power valve to two suction passages together in the collector.
Under this condition, the effective port length is equivalent to the length of the suction port provided indepen-
dently for each cylinder. This shortened port length results in enhanced engine output with reduced suction
resistance under high speeds.
COMPONENT DESCRIPTION
Power Valve
The power valve is installed in intake manifold collector and used to
control the suction passage of the variable induction air control sys-
tem. It is set in the fully closed or fully opened position by the power
valve actuator operated by the vacuum stored in the surge tank. The
vacuum in the surge tank is controlled by the VIAS control solenoid
valve.
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
VIAS control VIAS control solenoid valve Mass air flow sensor Amount of intake air
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Battery Battery voltage*
Engine coolant temperature sensor Engine coolant temperature
PBIB0843E
PBIB0946E
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
EC-529
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AUTOMATIC SPEED CONTROL DEVICE (ASCD)PFP:18930
System DescriptionEBS01FAX
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
BASIC ASCD SYSTEM
Refer to Owner's Manual for ASCD operating instructions.
Automatic Speed Control Device (ASCD) allows a driver to keep vehicle at predetermined constant speed
without depressing accelerator pedal. Driver can set vehicle speed in advance between approximately 40 km/
h (25 MPH) and 144 km/h (89 MPH).
ECM controls throttle angle of electric throttle control actuator to regulate engine speed.
Operation status of ASCD is indicated by CRUISE indicator and SET indicator in combination meter. If any
malfunction occurs in ASCD system, it automatically deactivates control.
NOTE:
Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws.
SET OPERATION
Press ASCD MAIN switch. (The CRUISE indicator in combination meter illuminates.)
When vehicle speed reaches a desired speed between approximately 40 km/h (25 MPH) and 144 km/h (89
MPH), press SET/COAST switch. (Then SET indicator in combination meter illuminates.)
ACCEL OPERATION
If the RESUME/ACCELERATE switch is pressed during cruise control driving, increase the vehicle speed until
the switch is released or vehicle speed reaches maximum speed controlled by the system.
And then ASCD will keep the new set speed.
CANCEL OPERATION
When any of following conditions exist, cruise operation will be canceled.
CANCEL switch is pressed
More than 2 switches at ASCD steering switch are pressed at the same time (Set speed will be cleared)
Brake pedal is depressed
Clutch pedal is depressed or gear position is changed to the neutral position (M/T models)
Vehicle speed decreased to 13 km/h (8 MPH) lower than the set speed
ESP/TCS system is operated
When the ECM detects any of the following conditions, the ECM will cancel the cruise operation and inform
the driver by blinking indicator lamp.
Engine coolant temperature is slightly higher than the normal operating temperature, CRUISE lamp may
blink slowly.
When the engine coolant temperature decreases to the normal operating temperature, CRUISE lamp will
stop blinking and the cruise operation will be able to work by pressing SET/COAST switch or RESUME/
ACCELERATE switch.
Malfunction for some self-diagnoses regarding ASCD control: SET lamp will blink quickly.
If MAIN switch is turned to OFF during ASCD is activated, all of ASCD operations will be canceled and vehicle
speed memory will be erased.
Sensor Input signal to ECM ECM function Actuator
ASCD brake switch Brake pedal operation
ASCD vehicle speed controlElectric throttle control
actuator Stop lamp switch Brake pedal operation
ASCD clutch switch (M/T) Clutch pedal operation
ASCD steering switch ASCD steering switch operation
Park/Neutral position (PNP)
switchGear position
wheel sensor* Vehicle speed
SERVICE DATA AND SPECIFICATIONS (SDS)
EC-531
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SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
Fuel PressureEBS010W1
Idle Speed and Ignition TimingEBS010W2
*: Under the following conditions:
Air conditioner switch: OFF
Electric load: OFF (Lights, heater fan & rear window defogger)
Steering wheel: Kept in straight-ahead position
Calculated Load ValueEBS010W3
Mass Air Flow SensorEBS010W4
*: Engine is warmed up to normal operating temperature and running under no-load.
Intake Air Temperature SensorEBS010W5
Engine Coolant Temperature SensorEBS010W6
Heated Oxygen Sensor 1 HeaterEBS010W7
Fuel pressure at idle
Approximately 350 kPa (3.5bar, 3.57kg/cm2 , 51psi)
Target idle speedQR20DEM/T No load* (in Neutral position) 650±50 rpm
A/T No load* (in P or N position)
700±50 rpm
QR25DEM/T No load* (in Neutral position)
A/T No load* (in P or N position)
Air conditioner: ONQR20DEM/T In Neutral position
725 rpm or more
A/T In P or N position
QR25DEM/T In Neutral position 750 rpm or more
A/T In P or N position 700 rpm or more
Ignition timingQR20DEM/T In Neutral position
15°±5° BTDC A/T In P or N position
QR25DEM/T In Neutral position
A/T In P or N position
Calculated load value% (Using CONSULT-II or GST)
At idle10 - 35
At 2,500 rpm10 - 35
Supply voltageBattery voltage (11 - 14V)
Output voltage at idle0.7 - 1.1*V (QR20DE)
0.8 - 1.2*V (QR25DE)
Mass air flow (Using CONSULT-II or GST)1.0 - 4.0 g·m/sec at idle*
4.0 - 10.0 g·m/sec at 2,500 rpm*
Temperature °C (°F) Resistance kΩ
25 (77)1.800 - 2.200
80 (176)0.283 - 0.359
Temperature °C (°F) Resistance kΩ
20 (68)2.1 - 2.9
50 (122)0.68 - 1.00
90 (194)0.236 - 0.260
Resistance [at 25°C (77°F)] 3.3 - 4.0Ω
EC-542
[QR (WITHOUT EURO-OBD)]
PREPARATION
Commercial Service ToolsEBS010WL
Tool name Description Description
Quick connector
releaseRemoving fuel tube quick connectors in engine
room
(Available in SEC. 164 of PARTS CATALOG: Part
No. 16441 6N210)
Fuel filler cap adapter Checking fuel tank vacuum relief valve opening
pressure
Socket wrench Removing and installing engine coolant
temperature sensor
Oxygen sensor thread
cleanerReconditioning the exhaust system threads
before installing a new oxygen sensor. Use with
anti-seize lubricant shown below.
a: 18 mm diameter with pitch 1.5 mm for
Zirconia Oxygen Sensor
b: 12 mm diameter with pitch 1.25 mm for
Titania Oxygen Sensor
Anti-seize lubricant
i.e.: (Permatex
TM
133AR or equivalent
meeting MIL
specification MIL-A-
907)Lubricating oxygen sensor thread cleaning tool
when reconditioning exhaust system threads.
PBIC0198E
S-NT653
S-NT705
AEM488
S-NT779
ENGINE CONTROL SYSTEM
EC-547
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System ChartEBS010WO
*1: This sensor is not used to control the engine system under normal conditions.
*2: This input signal is sent to the ECM through CAN communication line.
*3: This output signal is sent from the ECM through CAN communication line.
*4: With ESP models.
*5: Without ESP models.
*6: For QR25DE engine modelsInput (Sensor) ECM Function Output (Actuator)
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)
Mass air flow sensor
Engine coolant temperature sensor
Heated oxygen sensor 1
Throttle position sensor
Accelerator pedal position sensor
Park/neutral position (PNP) switch
Intake air temperature sensor
Power steering pressure sensor
Ignition switch
Battery voltage
Knock sensor
Refrigerant pressure sensor
Stop lamp switch
Heated oxygen sensor 2*1
TCM (Transmission control module)*2
ESP/TCS/ABS control unit*2 *4
ABS actuator and electric unit
(control unit)*2 *5
Air conditioner switch
Wheel sensor*2
Electrical load signal
ASCD steering switch*6
ASCD brake switch*6
ASCD clutch switch*6
Fuel injection & mixture ratio control Fuel injector
Electronic ignition system Power transistor
Fuel pump control Fuel pump relay
On board diagnostic system
MI (On the instrument panel)*
3
Heated oxygen sensor 1 heater control Heated oxygen sensor 1 heater
Heated oxygen sensor 2 heater control Heated oxygen sensor 2 heater
EVAP canister purge flow controlEVAP canister purge volume control
solenoid valve
Air conditioning cut control Air conditioner relay
Power valve control*
6VIAS control solenoid valve
ASCD vehicle speed control*
6Electric throttle control actuator
Cooling fan control Cooling fan relay
EC-548
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ENGINE CONTROL SYSTEM
Multiport Fuel Injection (MFI) SystemEBS010WP
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system under normal conditions.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor and the mass air
flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.
During warm-up
When starting the engine
During acceleration
Hot-engine operation
When selector lever is changed from N to D (A/T models)
High-load, high-speed operation
During deceleration
During high engine speed operation
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
3 and piston position
Fuel injection & mixture
ratio controlFuel injector Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Heated oxygen sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Knock sensor Engine knocking condition
Battery
Battery voltage*
3
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
Wheel sensor*
2Vehicle speed
Air conditioner switch Air conditioner operation
ENGINE CONTROL SYSTEM
EC-549
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MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better reduce CO, HC and NOx emissions. This system uses
heated oxygen sensor 1 in the exhaust manifold to monitor whether the engine operation is rich or lean. The
ECM adjusts the injection pulse width according to the sensor voltage signal. For more information about
heated oxygen sensor 1, refer to EC-666, "
DTC P0132 HO2S1" . This maintains the mixture ratio within the
range of stoichiometric (ideal air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the three way catalyst (manifold). Even if the switching
characteristics of heated oxygen sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal
from heated oxygen sensor 2.
Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.
Deceleration and acceleration
High-load, high-speed operation
Malfunction of heated oxygen sensor 1 or its circuit
Insufficient activation of heated oxygen sensor 1 at low engine coolant temperature
High engine coolant temperature
During warm-up
After shifting from N to D (A/T models)
When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from heated oxygen
sensor 1. This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to
the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as orig-
inally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic
changes during operation (i.e., injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value compared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensation used to maintain the mixture ratio at its theoretical
value. The signal from heated oxygen sensor 1 indicates whether the mixture ratio is RICH or LEAN compared
to the theoretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an
increase in fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation carried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
PBIB0121E
EC-550
[QR (WITHOUT EURO-OBD)]
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 four cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The four 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) SystemEBS010WQ
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
The ignition timing is controlled by the ECM to maintain the best air-
fuel ratio for every running condition of the engine. The ignition tim-
ing data is stored in the ECM. This data forms the map shown.
The ECM receives information such as the injection pulse width and
camshaft position sensor signal. Computing this information, ignition
signals are transmitted to the power transistor.
e.g., N: 1,800 rpm, Tp: 1.50 msec
A °BTDC
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
SEF337W
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
2 and 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*1Vehicle speed
SEF742M