HO2S HEATER CONTROL OPERATION [AJ]

HO2S (Front) Heater

- PCM runs the heater control with a 0% duty signal when the following conditions are met.

• The ignition switch is ON with the engine stopped

• Engine speed is above 4,000 rpm

• Charging efficiency is above 75%

- PCM runs the heater control with a 30% duty signal when the following conditions are met.

• When starting

• Engine speed below 4,000 rpm

• Battery voltage above 16 V

• Engine coolant temperature or intake air temperature is below 5 °C {41 °F}

• ECT sensor, TP sensor or IAT sensor has a malfunction

- PCM runs the heater control with a 100% duty signal when following conditions are met.

• At idle for a specified period after the engine is started when engine coolant temperature is 0-40 °C {32-104 °F} and above 70 °C {158 °F}.

HO2S (Rear) Heater (European (L.H.D.) Specs.)

- Engine speed below 4,000 rpm

- Charging efficiency below 75%