HEATED OXYGEN SENSOR (HO2S) HEATER CONTROL OPERATION [ZY, Z6]

id0140a0180200

Front HO2S

Operation condition

• The PCM operates the front HO2S heater according to engine operation conditions as shown in the table below.

Drive duty ratio

Engine operation conditions

30%
• At engine start
• During engine rotation except idling
• Engine coolant temperature is 5°C {41°F} or less.
• When a DTC indicating a damaged ECT sensor, TP sensor or IAT sensor is detected.
100%
• For a fixed period of time after engine start when the engine coolant temperature at engine start is 50°C {122°F} or less than the engine coolant temperature when the engine is stopped from a previous operation (differs from engine coolant temperature at engine start [lower water temperature→longer time]).

Inhibition conditions

• During torque reduction execution
• Engine speed 4,300 rpm or more
• During high load
• Engine stopped

Rear HO2S

Operation condition

• When all of the following conditions are met:
- After fixed period of time from engine start
- Engine speed is less than 2,700 rpm
- Throttle valve opening angle is less than 10%
- Intake air amount exceeds the specified value
- Except during TCS control