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:
Neutral Switch
Purpose/Function
Detects the neutral position of the shift lever.
Construction
Installed to the manual transaxle.
An ON/OFF type switch has been adopted.
Operation
Inputs the neutral switch on/off signal to the PCM.
The contact point is on ...
Transmission/Transaxle Abbreviations
AAS
Active Adaptive Shift
ABS
Antilock Brake System
ABDC
After Bottom Dead Center
ACC
Accessories
AFS
Adaptive Front Lighting System
ALC
...
Manifold Absolute Pressure (Map) Sensor
Purpose/Function
Detects the intake air pressure introduced into the cylinder as basic information
for mainly determining the fuel injection amount.
Detects the intake air pressure introduced into the cylinder and inputs it
to the PCM as an intake air pressure signal.
Cons ...