Circuit Description

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 .5 volt). As the throttle plate opens, the output signal increases so that at wide open throttle, the output will be high (about 5 volts).

DTC will set if MAP or TP sensor value is out of range for greater than 2 seconds, engine speed is 1600-4000 RPM, engine speed change is less than 100 RPM, EGR commanded steady, A/C command is unchanged and IAC change is less than 10 counts. DTC will also set when P0601, P0602, P1635, EGR, IAC, MAP or TP sensor DTCs have not been set.