Circuit Description

Manifold Absolute Pressure (MAP) sensor responds to changes in intake manifold pressure (vacuum). PCM applies 5-volt reference voltage to MAP sensor. Changes in pressure, resulting from engine load and RPM, are converted into a voltage signal monitored by PCM. A low voltage reading at PCM indicates low manifold pressure, and a high voltage at PCM indicates high manifold pressure. DTC will set when:

• Engine is running.
• MAP sensor value at engine cranking differs from engine running by less than .19 psi (1.3 kPa).
• Barometric pressure differs from MAP sensor pressure by less than .19 psi (33 kPa).
• Conditions must be present for at least 2 minutes.