MAP Sensor Scaling

Hi,

I have a few questions regarding MAP sensor scaling, when fitting a new map sensor and calibrating the data in the ecu. For instance the Hondata system has the Scalar and Offset values that need configured, and if I’m understanding correctly the Scalar is the conversion value used to convert the voltage output into a pressure value, and the Offset is used to describe the point at which the Scalar starts, since most sensors have a minimum voltage above 0v. Is this correct?

Unfortunately, most cars I’ve ran into have unknown MAP sensors and I have to measure the KoEov (Key On Engine Off) voltage and then play the with both the Offset and Scalar settings until the MAP sensor reads correctly and even then it’s never perfect. I’ve heard of the method of using an air pump and measuring the min. and max voltages /pressures of the sensor and then either plotting a graph or using the equation to calculate Scalar/Offset. I’m curious as if there is an easier way to do this or am I better off just advising people to get a new MAP sensor with correct calibration data. There are a number of preset calibrations that are close but I always have to mess with the settings and it’s never perfect.

Thank You

I'd always recommend that you purchase a MAP sensor with calibration data available. This sensor is one of the most critical to your ECU so you really want to be certain that the data the ECU is receiving is correct. You could calibrate an unknown sensor by comparing it to a known sensor at two pressure points, however with the low cost of MAP sensors this probably is pretty hard to justify.