DTC P0105: Map Sensor Circuit Range/Performance: Description
WARNING: This page is about a different car, the 2002 Saturn LW200, 2002 Saturn L200, and 2002 Saturn L100. However, it is still accessible from the selected car via links, so may be relevant.
PCM compares MAP sensor values with TP sensor values. The MAP sensor is a variable resistor that responds to changes in intake manifold pressure. Voltage ranges from 1.0-1.5 volts at idle (high vacuum) to 4.5-4.8 volts at wide open throttle (low vacuum). The TP sensor is a potentiometer which responds to changes in throttle plate angle. At closed throttle position, output of sensor is low (about .35 volt). As throttle plate opens, output signal increases (more than 4.6 volts). DTC sets when MAP and TP values are out of calibrated range from table values.