DTC P0105: Map Sensor Circuit: Description
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2001 Saturn SW2, 2001 Saturn SL2, 2001 Saturn SL1, 2001 Saturn SL, and 2001 Saturn SC2. However, it is still accessible from the selected car via links, so may be relevant.
PCM has internal tables that compare MAP sensor values with TP sensor values. MAP sensor is a variable resistor that responds to changes in intake manifold pressure. The voltage ranges from 1.0-1.5 volts at idle (high manifold vacuum) to 4.0-4.5 volts at wide open throttle (low manifold vacuum).
TP sensor is a potentiometer which responds to changes in throttle plate angle. At closed throttle position, output of the sensor is low (about 0.4 volt). As the throttle plate opens, the output signal increases so that at wide open throttle, the output will be high (about 4.7 volts).