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:

Blind Spot Monitoring (Bsm) Off Indicator Light
Purpose The BSM OFF indicator light informs the driver that the Blind Spot Monitoring (BSM) system is turned off or there is a malfunction in the system. Function The instrument cluster illuminates the BSM OFF indicator light based on the BSM system off signal sent via a CA ...

Floor Covering Removal/Installation
1. Disconnect the negative battery cable.. 2. Remove the following parts: a. Front scuff plate. b. Front side trim. c. Rear scuff plate. d. B-pillar lower trim. e. Rear seat cushion. f. Front seat. g. Lower anchor of the front seat belt (without lap pre-tensioner seat belt). h. La ...

Sas Control Module Configuration (Using Read/Write Function) [Standard Deployment Control System]
NOTE: When performing configuration, it is necessary to read the vehicle specification information from the SAS control module before replacing it. Connect the M-MDS to the vehicle and perform vehicle identification before removing the SAS control module. The vehicle specification i ...