Cartwaveforms > sensors > map sensor > MAP Sensor (Analog)
Download this waveform file | This is a good waveform |
|---|
MAP Sensor (Analog) Waveform Notes
This particular component can be either an integral part to the electronic control module or an individual component. The output from the external sensor will show a rise and fall voltage depending upon the vacuum seen. When the engine is stationary or the throttle is wide open, zero vacuum will be recorded and a voltage approaching 5 volts will be seen, as a vacuum is applied the voltage will reduce. The example waveform clearly demonstrates that at idle a voltage of around 1 volt is seen, and as the throttle is opened the vacuum in the manifold drops and a higher voltage for these conditions is seen. In this particular case the voltage is rising to almost 5 volts. The ‘hash’ on the waveform is due to the vacuum change from the induction pulses as the engine is running.
All voltages are similar between different manufacturers and a lower than anticipated voltage will produce a loss of power due to fuel starvation and conversely a higher voltage will cause over fueling and could eventually result in the failure of the catalytic converter if subjected to long term abuse. This high voltage could result from any number of problems but could be as simple as a split vacuum hose or incorrectly adjusted tappet clearances. The voltage from an integral MAP sensor can only be evaluated when a Fault Code Reader (FCR) is used due to the lack of access to the output voltage.
Share
Help!