The manifold absolute pressure (MAP) sensor responds to
any changes in the intake manifold pressure. The pressure changes as a result
of the engine load and speed. The MAP sensor converts this to a voltage
output.
A closed throttle on the engine coast down would produce a relatively
low MAP output voltage. A wide open throttle (WOT) would produce a high MAP
output voltage. This high output voltage is produced because the pressure
inside of the manifold is the same as outside the manifold. The MAP is
inversely proportional to what is measured on a vacuum gauge. The MAP
sensor is used for the following:
When the VCM detects a malfunction in the MAP sensor circuit, the following
DTCs will set: