Integrated Ambient Barometric Pressure Sensor

The MS S52 control module contains an integral ambient barometric pressure sensor. The sensor is part of the SKE and is not serviceable. The internal sensor is supplied with 5 volts. In return, the sensor provides a linear voltage of approximately 2.4 to 4.5 volts representative of barometric pressure (altitude). The barometric pressure signal along with calculated air mass provides an additional correction factor to further refine injection on time, and provides a base value to calculate the air mass being injected into the exhaust system by the secondary air injection system. This correction factor alters the secondary air injection on time, optimizing the necessary air flow into the exhaust system. Recognition of altitude above the accepted criteria postpones DM-TL activation for evaporative emission leak diagnosis.