Mazda CX-5 Service & Repair Manual: Air Fuel Ratio (A/F) Sensor Heater Control

Mazda CX-5 Service & Repair Manual / Engine / Control / Air Fuel Ratio (A/F) Sensor Heater Control

Outline

Based on the control of the A/F sensor heater, a stabilized oxygen concentration is detected even at low exhaust temperatures, and feedback control of fuel injection even at cold engine start is made possible for improved cold temperature exhaust emission performance.
Both emission performance and sensor protection have been improved by duty control of the heater according to engine operation conditions (exhaust gas temperature).
A pre-heater has been adopted to prevent water, produced from the exhaust system when the engine is started, from adhering to the sensor and damaging it.

Block Diagram

Operation

Pre-heater control

The A/F sensor heater is operated at a duty ratio of approx. 15% within the specified time directly after the engine is started.

Normal control

The PCM operates the A/F sensor based on the following control conditions:


Output duty ratio	Control condition
0%	Ignition switched off Engine stopped Engine start (cranking)
0?100% (Duty ratio determined by measuring the element temperature by the A/F sensor heater element impedance)	After engine warm-up (value fluctuates by battery condition, etc.)

Output duty ratio

Control condition

Ignition switched off
Engine stopped
Engine start (cranking)

0?100%

(Duty ratio determined by measuring the element temperature by the A/F sensor heater element impedance)

After engine warm-up (value fluctuates by battery condition, etc.)

Accelerator Pedal Position (App) Sensor

Purpose/Function Detects the accelerator pedal depression amount as basic information for mainly determining the throttle valve opening. Detects the accelerator pedal depression amou ...

Air Fuel Ratio (A/F) Sensor Inspection

A/F Sensor Inspection 1. Connect the M-MDS to the DLC?2. 2. Switch the ignition ON (engine on). 3. Warm up the engine to normal operating temperature. 4. Access the following PIDs using the M-M ...

Other materials:

Front Seat Rail Guide Cover Removal/Installation
WARNING: Handling a side air bag improperly can accidentally operate (deploy) the air bag, which may seriously injure you. Read the service warnings/cautions in the Workshop Manual before handling the front seat (side air bag integrated).. If the sliding mechanisms on both side ...

Clutch Release Collar Inspection [C66 M R]
CAUTION: Do not clean the clutch release collar with cleaning fluids or a steam cleaner because it is filled with grease. Operation Inspection 1. Turn the collar while applying force in the axial direction, and inspect for sticking, excessive resistance, and an abnormal noise. ...

Bsm Indicator Light Flashes While Not Under Bsm Indicator Light Flashing Conditions (No Combination Switch Operation (Turn Signal Switch)) [Blind Spot Monitoring (Bsm)]
Description BSM indicator light flashes while not under BSM indicator light-flashing conditions (no combination switch operation (turn signal switch) The BSM indicator light flashes despite not satisfying the BSM indicator light flashing ...