V50 L5-2.4L VIN 39 B5244S7 (2005)
The air conditioning (A/C) pressure sensor detects the pressure in the high-pressure side of the air conditioning (A/C) system. See also: Function See:
Powertrain Management/Computers and Control Systems/Description and Operation/Engine Control Module (ECM)/Function
The sensor is linear. It is grounded in the control module and supplied with a 5 Volt current from the control module. A linear signal (between 0-5 V
depending on the pressure in the air conditioning (A/C)) is transmitted to the control module. Low pressure produces low voltage, high pressure produces
high voltage. The air conditioning (A/C) pressure sensor is affected by the pressure in the high-pressure pipe of the air conditioning (A/C) system
(narrow pipe).
The engine control module (ECM) can diagnose the air conditioning (A/C) pressure sensor. The sensor value can be read off using VIDA.
Heated oxygen sensors (HO2S)
Front heated oxygen sensor (HO2S)
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 (HO2S) uses current control and its signal characteristic is linear. With a linear signal characteristic, the amplitude of the
signal curve is low when the oxygen content in the exhaust gases changes. 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 (HO2S) needs reference air from the surrounding
air. This reference air reaches the heated oxygen sensor (HO2S) 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: Powertrain Management/Computers and Control Systems/Description and Operation/Heated Oxygen Sensor (HO2S) Diagnostic
VIDA can be used to read off the calculated lambda value from the heated oxygen sensor.
