Secondary Air Injection (Air) Control Outline - Mazda RX-8 2004 Service Highlights

ECT spark advance correction
• Corrects other than during idling.
• Stabilizes combustion by correction of ignition timing in consideration of friction loss when the engine is at a low
temperature.
• The correction amount is determined by the ECT and charging efficiency, and increases as the ECT
decreases.
IAT spark advance correction
• Corrects ignition timing according to the IAT.
• The correction amount is determined by the IAT, idling condition and charging efficiency, and increases as the
IAT decreases.
Types of spark advance correction
• Spark advance correction is as follows:
Knock feedback correction
• When knocking is detected, ignition timing is retarded, stabilizing the combustion condition.
Idling stabilization correction
• Correction stabilizes engine speed during idling. The correction amount is determined by the actual engine
speed and the average engine speed.
Fast idle correction
• At cold-engine start, the correction is performed to accelerate secondary air response (reburn), decrease
unburnt gas, and rapidly activate the catalytic converter.
Low temperature correction
• Performs spark advance correction of ignition timing to stabilize combustion during low temperature. Low
temperature correction performs advance of ignition timing when ECT is less than 90°C {194°F} and the AP
is depressed, and is determined by ECT, charging efficiency and engine speed.
Acceleration correction
• Performs retard correction of ignition timing to prevent knocking at acceleration from a standstill. Correction
amount is determined by the amount of throttle valve change, the charging efficiency and the ECT.
Fuel cut recovery correction
• Performs retard correction of ignition timing during recovery from deceleration fuel cut to prevent shock
during fuel cut recovery. Correction amount is determined by idling condition, A/C condition and engine
speed.
Surging correction
• Performs spark retard correction due to acceleration vibration to stabilize acceleration. Correction amount
is determined by the engine speed and the amount of engine speed change.
Acceleration shock correction
• Gradually restores ignition timing after it is retarded for a fixed period of time to inhibit shock during
acceleration.
A/C off correction
• The retard correction is performed to prevent engine speed fluctuation due to load decrease when the A/C
switch is off. The correction amount is determined by the engine speed and the charging efficiency, and
decreases as the engine speed and the charging efficiency are high.
Traction correction
• The spark timing is retarded following a torque down request from the DSC HU/CM and TCM, reducing
engine torque.
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SECONDARY AIR INJECTION (AIR) CONTROL OUTLINE

• The AIR control activates the catalytic converter rapidly at cold-engine start.
• The PCM controls the AIR pump relay and the AIR solenoid valve.
• After the catalytic converter reaches the activation temperature, AIR control stops.
• For the construction and operation of the AIR system, refer to the emission system and AIR system. (See 01–
16–3 SECONDARY AIR INJECTION (AIR) SYSTEM OUTLINE.)
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CONTROL SYSTEM
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