Map Airflow Pressure Sensor

Basically a map sensor reads the amount of air pressure in relation to vacuum inside the intake manifold either directly or using a vacuum hose.

Map airflow pressure sensor.

A failed map sensor has serious implications on fuel control vehicle tailpipe emissions and fuel economy. Benji jerew flickr cc by 2 0. This map sensor is mounted directly to the intake manifold but others might be connected by a hose. The computer may be using the map sensor to measure only the positive air pressure coming from a turbocharger or supercharger.

A faulty map sensor affects engine performance but can also affect transmission s shift timing. This is because the map sensor measures absolute pressure based on a perfect vacuum rather than atmospheric pressure. You can usually tell if you have a map sensor if you cannot find a maf sensor in the intake air tube before the throttle body. The ecm and the tcm monitor engine load through the map and maf sensors.

The map sensor is usually mounted directly to the intake manifold somewhere after the throttle body though some are mounted on the firewall or elsewhere in the engine bay connected to the intake manifold via a vacuum line. Then it translates this pressure into a voltage signal that the sensor feeds to the power control module pcm your car s computer. In fuel injected automotive engines a manifold absolute pressure map sensor is used to continuously monitor the amount of air flowing into the engine so the computer can calculate air density adjust the amount of fuel to spray into the combustion chamber and adjust the ignition timing. Symptoms of a bad or failing map sensor include.

The ecm uses map sensor data to run crucial calculations such as engine load fuel injector pulse and spark advance. Maf and map sensors. Map manifold absolute pressure and is a sensor to measure vacuum the computer calculates the engine air flow based on the vacuum throttle position and intake air temperature. The map manifold absolute pressure sensor senses engine load through pressure in the intake manifold.

Engines that use a map sensor are typically fuel injected the manifold absolute pressure sensor provides instantaneous manifold pressure information to the engine s electronic control unit ecu. Map sensor and you. This combo may also be found in setups where a larger maf may become too turbulent at low load and the maf is used at high load for more accuracy in a naturally aspirated motor. The computer also measures the barometric pressure using the map sensor before the engine cranks this lets the computer compensate for altitude or how dense the air is.

At 20 hg the map sensor will indicate about 5 psi.