Mazda CX-5 Service & Repair Manual: Heated Oxygen Sensor (HO2 S) Heater Control
Outline
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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.
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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
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The PCM operates the HO2S heater based on the following control conditions.
|
Output duty ratio |
Control condition |
|
0% |
|
|
30% |
|
|
0?100% (Determined by engine speed and charging efficiency) |
|
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:
Electric Power Steering (Eps) Motor
Purpose, Function
The EPS motor is driven by the control current from the EPS CM (control module)
and generates assist torque to manual steering mechanism.
Construction
The EPS motor is installed to the steering column with an integrated EPS
CM.
The EPS motor is a b ...
Presilencer
Purpose, Function
Reduces the exhaust noise.
Construction
The presilencer is installed to the rear of the TWC.
2WD
AWD
The presilencer consists of the filters, stuffing and wool-stainless.
2WD
AWD
...
Camshaft Position (CMP) Sensor
Purpose/Function
Detects the camshaft speed as basic information for mainly determining the
fuel injection timing and ignition timing.
Detects the camshaft speed and inputs it to the PCM as a CMP signal.
Construction
Intake CMP sensor
Installed on the cylinder head.
...
