V50 AWD L5-2.5L Turbo VIN 68 B5254T3 (2005)
Caution! The air lines for the heated oxygen sensors must not be trapped or damaged in any way. The connectors for the heated oxygen sensors
must not be greased under any circumstances. The oil in the grease would disrupt the reference air and the function of the heated oxygen
sensors.
The front heated oxygen sensor (HO2S) is used to provide the engine control module (ECM) with information about the remaining oxygen content of the
exhaust gases in front of the three-way catalytic converter (TWC). This is so that the Engine Control Module (ECM) can continually check the
combustion so that lambda=1. lambda=1 is the ideal fuel-air ratio, with 14.7 kg air per 1 kg fuel.
The heated oxygen sensor uses current control and its signal characteristic is linear. With a linear signal characteristic, the amplitude of the signal curve
is low when changing the oxygen content in the exhaust gases. The probe consists of a preheating element (see "Pre-heating heated oxygen sensors
(HO2S)") and the actual lambda sensor. The lambda sensor is an oxygen-sensitive ceramic body consisting of zirconium oxide. The control module
supplies power to the ceramic body, which reacts to the oxygen content of the exhaust gases. This in turn affects the signal to the engine control module
(ECM). In order to determine the oxygen content in the exhaust pipe, the heated oxygen sensor needs reference air from the surrounding air. This
reference air reaches the heated oxygen sensor via the air lines.
Caution! The air lines for the heated oxygen sensors must not be trapped or damaged in any way. The connectors for the heated oxygen sensors
must not be greased under any circumstances. The oil in the grease would disrupt the reference air and the function of the heated oxygen
sensors.
The engine control module (ECM) can diagnose the heated oxygen sensor (HO2S). For more information, see: Heated oxygen sensor (HO2S) diagnostic
See: Description and Operation/Heated Oxygen Sensor (HO2S) Diagnostic
VIDA can be used to read off the calculated lambda value from the heated oxygen sensor.
Rear heated oxygen sensor (HO2S)
