SUZUKI MAP SENSOR 18590-72F21

Function and technical context

The MAP (Manifold Absolute Pressure) sensor measures the absolute pressure in the intake manifold of the outboard engine and sends that information to the electronic engine management unit. From this reading, the ECM precisely calculates the amount of fuel to inject and the optimal ignition point in each cycle, thus regulating the air-fuel mixture in real time. This component is part of the electronic engine management system and is critical for the correct functioning of the fuel injection. A deteriorated or defective MAP sensor causes the ECM to work with erroneous pressure data, which directly translates into irregular combustion, loss of power and high fuel consumption.

When to replace this part?

The most common symptoms of a bad MAP sensor include unstable or irregular idling, difficult cold starting, choppy acceleration, and activation of the malfunction warning light on the boat's dashboard. In electronic injection engines, it is recommended to check this sensor during each seasonal maintenance, especially if the engine accumulates more than 300 hours of use or has been exposed to intense vibration or humidity. Replacing it preventively in the event of any symptoms avoids an unexpected stoppage at sea and the cost of a more complex fault diagnosis.