GM Map Identification


The easiest way to tell if you have a 1, 2, or 3 bar map is to apply 5 volts to it and read the voltage on the output

At atmospheric pressure (in low altitudes) a 1 bar will show about 4.75V, a 2 bar about 2.25V, and a 3 bar about 1.5v at higher altitudes the readings will be somewhat lower

  • 1 Bar MAP sensors are used on NA(naturally aspirated) vehicles.

  • 2 Bar MAP Sensors are used on forced induction vehicles(Turbo & Supercharged). They can measure up to 2x the atmospheric pressure(29.4psi), so that means it can measure up to 14.7psi boost(the atmosphere is 14.7psi + 14.7psi from the turbo/supercharger).

  • 3 Bar MAP sensors can measure up to 44.1psi, which translates to 29.7psi boost from a Turbo/supercharger