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 MS S52 monitors barometric pressure for the following reasons:
- The barometric pressure signal along with calculated air mass provides an additional correction factor to further refine injection "on" time.
- 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 postponing DM-TL activation for evaporative emission leak diagnosis.