Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Barometric Pressure Sensor: Description and Operation

Barometric Pressure (BP) Sensor:






PURPOSE
The Barometric Pressure (BP) sensor provides an input signal that the Electronic Control Assembly (ECA) uses to compensate for changes in atmospheric pressure. The ECA calculates sensor input to calculate air/fuel ratio, idle speed, purge flow, and A/C cutoff.

OPERATION
The BP sensor is a frequency generating device producing varying signals depending on the amount of barometric (atmospheric) pressure.