Mazda X-5. Manual — part 38

CONTROL SYSTEM

01–40–25

01–40

ELECTRONIC SPARK ADVANCE (ESA) CONTROL BLOCK DIAGRAM [LF]

E5U014000000N32

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TR SWITCH (AT)

IAT SENSOR

MAF SENSOR

CMP SENSOR

CKP SENSOR

ECT SENSOR

KS

NEUTRAL SWITCH (MT)

CPP SWITCH (MT)

BRAKE SWITCH

NO.1, NO.2

BATTERY

GENERATOR

(TERMINAL P: STATOR COIL)

VEHICLE SPEED SIGNAL

IGNITER OPERATION TIME

IGNITION TIMING

FIXED
IGNITION

CYCLE ESTIMATED
IGNITION

IDLE SPARK
ADVANCE

BASIC SPARK
ADVANCE

CORRECTIONS

IGNITION COIL

PCM

TP SENSOR NO.1, NO.2

APP SENSOR NO.1, NO.2

A/C AMPLIFER

REFRIGERANT PRESSURE

SWITCH (HIGH, LOW )

TCM (AT)

E5U140ZT5004

CONTROL SYSTEM

01–40–26

ELECTRONIC SPARK ADVANCE (ESA) CONTROL OPERATION [LF]

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Ignition Method

• The PCM excites the ignition coils employing either fixed ignition or cycle estimated ignition according to engine

operation conditions.

Ignition
method

Ignition timing

Ignition coil energization period

Fixed

ignition

Fixed at BTDC 8

°

Fixed period at BTDC 8

° 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

-180

°

No.2

MAXIMUM VALVE TIMING RETARD CONDITION

CRANK ANGLE

FIXD IGNITION CYLINDER No.

No.1 CYLINDER APPROX. BTDC 8

°

CKP SENSOR SIGNAL

CKP SENSOR SIGNAL

CMP SENSOR SIGNAL

CMP SENSOR SIGNAL

FIXD IGNITION CYLINDER No.

No.2

No.1

No.3

No.4

No.2

No.2

No.1

No.3

No.4

180

°

360

°

540

°

0

°

MAXIMUM VALVE TIMING ADVANCE CONDITION

E5U140ZT5102

CONTROL SYSTEM

01–40–27

01–40

Determination of Ignition Timing
Division of control zones

• 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.

Ignition timing calculation method table

A: Ignition timing base, B: Correction for ignition timing

THROTTLE
VALVE
POSITION

ENGINE SPEED

START
ZONE

REGULAR ZONE

IDLE ZONE

OPEN

CLOSED

LOW

HIGH

C3U0140S020

Control zone

Control condition

Ignition method

Start zone

Engine speed is 500 rpm or less.
When MAF sensor is damaged.

Fixed ignition

Idle zone

Fully-closed throttle valve when engine speed is the
target idle speed + 1,750 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

Fixed ignition

Fixed at BTDC approx. 8

° CA

A

Cycle
estimated
ignition

Idle spark
advance

Set value according to target speed and charging efficiency

*

A

Basic spark
advance

Set value according to engine speed and charging efficiency

*

A

Star

t zone

Idling zone

Cyc

le estimated

zone

CONTROL SYSTEM

01–40–28

*

: Charging efficiency is ratio of actual intake air amount to maximum air charging amount (mass volume) of

cylinder. This value increases proportionately to the increase in engine load.

Ignition Inhibition Condition

• When receiving an engine stop request signal from the immobilizer system, the PCM force-stops control of

ignition coils. As a result, the engine does not start.

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EVAPORATIVE PURGE CONTROL OUTLINE [LF]

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• An appropriate amount of evaporative gas is fed into the dynamic chamber by the driving of the purge solenoid

valve according to the engine operation conditions to ensure driveability and prevent release of evaporative gas
into the atmosphere.

• The PCM determines the engine operation conditions based on the signals from the input devices indicated in

the figure below to drive the purge solenoid valve. For the construction/operation of the purge solenoid valve,
refer to “EMISSION SYSTEM, PURGE SOLENOID VALVE, CONSTRUCTION/OPERATION”.

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Correction

Engine coolant
temperature
advance
correction

Purpose: Ensures combustion stability when engine coolant temperature is
low

Except during idling

• High charging efficiency

*

, low engine coolant temperature

→large

correction

B

B

Warm-up
promotion spark
retard
correction

Purpose: Activates the catalytic converter earlier

Approx. 50 s after engine start

• According to engine coolant temperature→correction

B

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

B

EGR correction

Purpose: Prevents deviation of required ignition timing during EGR gas feed

When EGR valve position is the specified value or more except

during EGR valve initialization

• According to engine speed and charging efficiency

*

→correction

B

Shift spark
retard/ advance
corrections (AT)

Purpose: Reduce shift shock during upshifting or manual downshifting.

Determined according to torque reduction/increase request

signals from the TCM.

• Large torque reduction request during upshifting→large spark retard

correction

• Large torque increase request during manual downshifting→large spark

advance correction

B

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

B

B

Acceleration
spark retard
correction

Purpose: Prevents knocking and shock during sudden acceleration

Acceleration when charging efficiency

*

volume increase

(acceleration amount) is specified value or more

• High acceleration amount→high retard

B

Standing start
spark retard
correction

Purpose: Prevents shock when vehicle accelerates from a standing start

When vehicle accelerates from a standing start

• According to engine speed, throttle valve opening angle, engine coolant

temperature and intake air temperature

→correction

B

Knocking spark
retard
correction

Purpose: Knocking suppression

When knocking is detected while driving under high load

• Large amount of knocking→large correction

B