Circuit Description

Barometric Pressure (BARO) sensor and circuitry are located within PCM. Barometric pressure sensor represents barometric pressure and is used to compensate for altitude changes. Barometric pressure sensor reading is displayed from PCM using a scan tool when ignition is on and engine is off. DTC will set when difference between barometric pressure and manifold absolute pressure is 3.8 psi (26 kPa) or greater with ignition on and engine cranked for 2 seconds. When DTC sets, MIL will illuminate after 2 consecutive ignition cycles in which diagnostic runs with active fault. PCM will record operating conditions at time of diagnostic failure and store information in FREEZE FRAME/FAILURE RECORDS data buffer.