Nissan Versa

 Sedan Service Manual

Engine » Engine control system (EC) » Engine control system
Heated Oxygen Sensor 2

The heated oxygen sensor 2, after three way catalyst (manifold), monitors the oxygen level in the exhaust gas.

Even if switching characteristics of the air fuel ratio (A/F) sensor 1 are shifted, the airfuel ratio is controlled to stoichiometric, by the signal from the heated oxygen sensor 2.

This sensor is made of ceramic zirconia. The zirconia generates voltage from approximately 1 V in richer conditions to 0 V in leaner conditions.

Under normal conditions the heated oxygen sensor 2 is not used for engine control operation.

Heated Oxygen Sensor 2 Heater

SYSTEM DESCRIPTION

The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed, amount of intake air and engine coolant temperature.

OPERATION

Ignition Coil With Power Transistor

The ignition signal from the ECM is sent to and amplified by the power transistor. The power transistor turns ON and OFF the ignition coil primary circuit. This ON/OFF operation induces the proper high voltage in the coil secondary circuit.

Accelerator Pedal Position Sensor

Air Fuel Ratio Sensor 1

Air Fuel Ratio Sensor 1 Heater

Battery Current Sensor

Camshaft Position Sensor

Crankshaft Position Sensor

Engine Oil Temperature Sensor

EVAP Canister Vent Control Valve

Exhaust Valve Timing Control Solenoid Valve

Fuel Injector

Fuel Pump

Heated Oxygen Sensor 2

Intake Air Temperature Sensor

Intake Valve Timing Control Solenoid Valve

Malfunction Indicator Lamp (MIL)

Mass Air Flow Sensor

Oil Pressure Warning Lamp

Throttle Position Sensor