Integrated Ambient Barometric Pressure Sensor
The ME 7.2 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 it provides a linear voltage of approximately 2.4 to 4.5 volts representative of barometric pressure (altitude). The ME 7.2 monitors barometric pressure because pressure signal along with calculated air mass provides an additional correction factor to further refine injection ON time and it 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. See Fig 1.