Mazda CX-5 Service & Repair Manual: Heated Oxygen Sensor (HO2 S) Heater Control

Mazda CX-5 Service & Repair Manual / Engine / Control / Heated Oxygen Sensor (HO2 S) Heater Control

Outline

Based on the control of the HO2S 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)

Block Diagram

Operation

The PCM operates the HO2S heater based on the following control conditions.


Output duty ratio	Control condition
0%	Engine stopped Fuel cut injection control is in engine start zone Engine coolant temperature is -10 °C {14 °F}or less Other than battery voltage of 10—16 V Within a fixed period of time after engine start (varies according to engine coolant temperature)
30%	HO2S not activated
0?100% (Determined by engine speed and charging efficiency)	Other than the above

Engine Coolant Temperature (ECT) Sensor

Purpose/Function Detects the ECT as basic information for mainly determining the fuel injection amount. Detects the ECT and inputs it to the PCM as an ECT signal. The ECT sen ...

Heated Oxygen Sensor (HO2 S) Inspection

HO2S 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-MDS.. ...

Other materials:

Clock Spring Adjustment [Standard Deployment Control System]
1. Set the front wheels straight ahead. CAUTION: The clock spring will break if over?wound. Do not forcibly turn the clock spring. 2. Turn the clock spring clockwise until it stops. 3. Turn the clock spring counterclockwise approx. 2 turns. 4. Align the mark on the clo ...

Front Over Fender Removal/Installation
1. Remove fastener A. 2. Pull the front over fender lower in the direction of the arrow (1) while removing hook B and pin C. 3. Remove fasteners D. 4. Pull the front over fender upper in the direction of the arrow (2) while removing clips E. 5. Install in the reverse order of ...

Front Door Latch And Lock Actuator Removal/Installation
1. Perform the front door glass preparation.. 2. Disconnect the negative battery cable.. 3. Remove the following parts: a. Inner garnish. b. Front door trim. c. Inner handle. d. Front door glass. e. Front door module panel. f. Front door key cylinder. 4. Remove the door lock knob c ...