Air pressure sensor /MAP

Absolute pressure sensors - MAP

How it works:
To optimise the air-fuel mixture and improve combustion and ignition performance, the volume of air admitted to the engine must be constantly monitored and adjusted. Manifold absolute pressure (MAP) sensors are essential for this process.
A compact semiconductor vacuum sensor, the MAP sensor takes advantage of the piezoelectric resistance effect, where the electrical resistance changes when pressure is applied to the silicon. This effect is used to measure the pressure in the intake manifold coming downstream of the throttle valve. The pressure measurement is then transmitted to the engine ECU via electrical signals and is used to calculate the intake air volume. Once this is calculated, the ECU can adjust engine performance to ensure optimum control of the air-fuel ratio.
Although this is the primary function of MAP sensors, these parts are also used to measure boost pressure coming into the throttle valve and turbo gallery pressure to optimize engine performance in severe turbocharging or supercharging environments.

Features and Benefits:

⦁ Bare chip mounting means fewer components and a compact size.
⦁ On-chip noise cancellation reduces the number of components required.
⦁ Durable two-layer surface copes with the harsh environment of the intake manifold.
⦁ Link connections offer greater reliability and easier installation.

What are the possible failures of MAP sensors?

⦁ Any substances or high humidity in the intake air entering the pressure orifice can cause a failure of the MAP sensors.
⦁ Vacuum leaks in the intake manifold systems or the hose connecting the MAP sensor to the engine can cause the MAP sensor to malfunction.
⦁ Short circuits and openings in the MAP sensor wiring circuit can cause a discrepancy in characteristics or malfunction.

What are the symptoms of MAP sensors?

⦁ Loss of engine power.
⦁ Rough and unstable idling.
⦁ Poor driving, including hesitation during acceleration.
⦁ Locks shortly after starting or when the accelerator is pressed or released.

How to prevent and solve MAP sensor failures?

⦁ A problem with the MAP sensor can cause the engine warning lamp to illuminate. This fault is stored under the Diagnostic Trouble Code (DTC) in the engine ECU (P0105...P0109) and can be inspected by a DTC scan tool.
⦁ A faulty MAP sensor may not disable the vehicle, but should be replaced as soon as possible to avoid potential engine damage in rich or lean fuel conditions caused by a malfunctioning MAP sensor.
⦁ Make sure there are no anomalies in the intake manifold vacuum due to leaks or other system problems.