Determination Of Ignition Timing - Mazda 2006 MX-5 Service Highlights

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.
Control zone
Engine speed is 500 rpm or less.
Start zone
When MAF sensor is damaged.
Fully-closed throttle valve when engine speed is the
Idle zone
target idle speed + 1,750 rpm or less
Cycle estimated
Engine operation except start zone and idle zone
zone
Ignition timing calculation method table
Contents
Fixed ignition
Cycle Idle spark
estimated advance
ignition
Basic spark
advance
CONTROL SYSTEM
Control condition
Calculation method or determination method for ignition timing,
advance value and correction
Fixed at BTDC approx. 8 ° CA
Set value according to target speed and charging efficiency
Set value according to engine speed and charging efficiency
OPEN
START
THROTTLE
ZONE
VALVE
POSITION
IDLE ZONE
CLOSED
LOW
ENGINE SPEED
Ignition method
Fixed ignition
Determines ignition timing adding each correction
to the idle spark advance
Determines ignition timing adding each correction
to the basic spark advance
A: Ignition timing base, B: Correction for ignition timing
*
*
REGULAR ZONE
HIGH
C3U0140S020
Control zone
A
A
A
01–40–27
01–40