Failed Manifold Absolute Pressure Sensor (MAP Sensor)

The Manifold Absolute Pressure sensor is used for engine load input. The Powertrain Control Module uses this and other input to calculate the correct amount of fuel to inject into cylinders.

A failed Manifold Absolute Pressure sensor will have serious implications on fuel control, car tailpipe emissions and fuel economy. What are the symptoms of a bad or failing Manifold Absolute Pressure sensor?

• Excessive fuel consumption

Manifold Absolute Pressure sensor measures high intake manifold pressure indicates high engine load to the Powertrain Control Module, which results in an increase of fuel being injected into the engine and decreases overall fuel economy.

• Lack of power

Manifold Absolute Pressure sensor that measures low intake manifold pressure indicates low engine load to the Powertrain Control Module, it responds by reducing the amount of fuel being injected into the engine. The engine isn’t as powerful as it was before, combustion chamber temperatures are increased, which will also increase the amount of oxides of nitrogen production within the engine(NOx is also a chemical component of smog).

• Failed emissions test

A bad Manifold Absolute Pressure sensor will cause the car fail an emissions test. The tailpipe emissions may show a high level of hydrocarbons, high NOx production, low CO2, or a high level of carbon monoxide.

 

Reference

Yourmechanic.com. (2018). Symptoms of a Bad or Failing Manifold Absolute Pressure Sensor (MAP Sensor) | YourMechanic Advice. [online] Available at: https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-manifold-absolute-pressure-sensor-map-sensor [Accessed 22 May 2018].