ELECTRONIC SPARK ADVANCE OPERATION [MZR 1.6]

Ignition method	Ignition timing	Ignition coil energization period
Fixed ignition	Fixed at BTDC 6 °	Fixed period at BTDC 6 ° to end of energization
Cycle estimated ignition	Ignition at timing appropriate to engine operation conditions based on input signals	• Energization time (ignition coil energization time) to igniter is determined according to battery voltage • Cylinder independent ignition

Ignition method

Ignition timing

Ignition coil energization period

Fixed ignition

Fixed at BTDC 6 °

Fixed period at BTDC 6 ° to end of energization

Cycle estimated ignition

Ignition at timing appropriate to engine operation conditions based on input signals

• Energization time (ignition coil energization time) to igniter is determined according to battery voltage

• Cylinder independent ignition

• The PCM divides the engine control operations into each control zone according to the engine speed and throttle valve opening angle to determine the ignition timing by each of the control zones to perform optimum ignition control under all engine operation conditions.

atraan00000177

Control zone	Control condition	Ignition method
Start zone	Engine speed is 500 rpm or less or when mass airflow sensor is damaged.	Fixed ignition
Idle zone	Fully-closed throttle valve when engine speed is the target idle speed + 650 rpm or less.	Determines ignition timing adding each correction to the idle spark advance
Cycle estimated zone	Engine operation except start zone and idle zone	Determines ignition timing adding each correction to the basic spark advance

Control zone

Control condition

Ignition method

Start zone

Engine speed is 500 rpm or less or when mass airflow sensor is damaged.

Fixed ignition

Idle zone

Fully-closed throttle valve when engine speed is the target idle speed + 650 rpm or less.

Determines ignition timing adding each correction to the idle spark advance

Cycle estimated zone

Engine operation except start zone and idle zone

Determines ignition timing adding each correction to the basic spark advance

Contents	Calculation method or determination method for ignition timing, advance value and correction	Control zone
Correction	Engine coolant temperature spark advance correction	Purpose: Protects combustion stability when engine coolant temperature is low. Except during idling • High charging efficiency^*1, low engine coolant temperature→large correction		×	×
Warm-up promotion spark retard correction	Purpose: Activates the catalytic converter earlier Constant period after engine start • According to engine coolant temperature→correction		×
Feedback correction	Purpose: Ensures idling stability During idling (inhibited during test mode) • Large difference between actual engine speed and target engine speed→large correction • Small difference between actual engine speed and target engine speed→small correction		×
Correction	Variable tumble spark advance correction	Purpose: ignition timing optimization during variable tumble control Controls spark advance amount according to the variable tumble shutter valve open/closed condition • Closed condition→small spark advance amount • Open condition→large spark advance amount			×
Shift spark retard correction (ATX)	Purpose: Reduces shift shock during shifting Determined according to torque reduction request signal from the ATX control • Large torque down request during shifting→large correction			×
Deceleration fuel cut recovery retard correction	Purpose: Reduces shock after recovery from deceleration fuel cut and during re-acceleration while in deceleration fuel cut Re-acceleration after recovery from deceleration fuel cut and while in deceleration fuel cut • Low engine coolant temperature→large correction		×	×
Acceleration spark retard correction	Purpose: Prevents knocking and shock during sudden acceleration Acceleration when charging efficiency^*1volume increase (acceleration amount) is constant value or more. • High acceleration amount→high retard			×
Knocking spark retard correction	Purpose: Knocking suppression When knocking is detected while driving under high load • Large amount of knocking→large correction			×

Contents

Calculation method or determination method for ignition timing, advance value and correction

Control zone

Fixed ignition

Fixed at BTDC approx. 6 °CA

Cycle estimated ignition

Idle spark advance

Set value according to target speed and charging efficiency^*1

Basic spark advance

Set value according to engine speed and charging efficiency^*1

Correction

Engine coolant temperature spark advance correction

Purpose: Protects combustion stability when engine coolant temperature is low.

Except during idling

• High charging efficiency^*1, low engine coolant temperature→large correction

Warm-up promotion spark retard correction

Purpose: Activates the catalytic converter earlier

Constant period after engine start

• According to engine coolant temperature→correction

Feedback correction

Purpose: Ensures idling stability

During idling (inhibited during test mode)

• Large difference between actual engine speed and target engine speed→large correction

• Small difference between actual engine speed and target engine speed→small correction

Correction

Variable tumble spark advance correction

Purpose: ignition timing optimization during variable tumble control

Controls spark advance amount according to the variable tumble shutter valve open/closed condition

• Closed condition→small spark advance amount

• Open condition→large spark advance amount

Shift spark retard correction (ATX)

Purpose: Reduces shift shock during shifting

Determined according to torque reduction request signal from the ATX control

• Large torque down request during shifting→large correction

Deceleration fuel cut recovery retard correction

Purpose: Reduces shock after recovery from deceleration fuel cut and during re-acceleration while in deceleration fuel cut

Re-acceleration after recovery from deceleration fuel cut and while in deceleration fuel cut

• Low engine coolant temperature→large correction

Acceleration spark retard correction

Purpose: Prevents knocking and shock during sudden acceleration

Acceleration when charging efficiency^*1volume increase (acceleration amount) is constant value or more.

• High acceleration amount→high retard

Knocking spark retard correction

Purpose: Knocking suppression

When knocking is detected while driving under high load

• Large amount of knocking→large correction