300SD (140.134) L6-3.5L DSL Turbo (603.971) (1993)
Absolute Pressure Sensor: Description and Operation
Atmospheric Pressure Sensor (Integrated into Control Unit)
Depending on altitude or atmospheric pressure, the atmospheric pressure sensor influences EGR volume. The atmospheric pressure sensor sends the
control unit a voltage signal which is proportionate to the atmospheric pressure (i.e. low voltage at low pressure). In other words, the control unit
determines EGR volume according to the relative atmospheric pressure via a reduction in vacuum transducer current.