S10/T10 Blazer 2WD L4-119 1.9L VIN A 2-BBL (1984)
Barometric Pressure Switch: Description and Operation
1984
The barometric pressure switch, provides an input to the ECM when barometric pressure falls below the switch calibration point due to an increase in
altitude. This input causes the ECM to override the ``Check Engine'' light caused by rich oxygen sensor error.
