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

Manifold Absolute Pressure (MAP) Sensor:




The Single Board Engine Controller (SBEC) controls the barometric read solenoid. The solenoid is located in the Manifold Absolute Pressure (MAP) vacuum line, near the MAP sensor. The solenoid controls whether manifold pressure or atmospheric pressure is applied to the MAP sensor. Manifold pressure is normally applied to the MAP sensor, and atmospheric pressure is applied periodically to measure barometric pressure. Atmospheric pressure is applied to the MAP sensor once per throttle closure, but no more often than once in a three minute time period and within a specific rpm range. The main purpose for this input is to control turbo boost.