DTC P0120 - Throttle Position (TP) Sensor Circuit Malfunction: Condition

WARNING: This page is about a different car, the 1997 Mazda Millenia. However, it is still accessible from the selected car via links, so may be relevant.

DTC is set when input voltage from TP sensor is less than .1 volt or greater than 4.8 volts when ignition is turned on. Possible causes are:

TP sensor malfunction.
Open or short circuit between terminal No. 3A on Engine Control Module (ECM) and terminal "A" on TP sensor.
Open or short circuit between terminal No. 3B on Engine Control Module (ECM) and terminal "B" on TP sensor.
Open or short circuit between terminal No. 3AB on Engine Control Module (ECM) and terminal "D" on TP sensor.
Mass Air Flow (MAF) sensor malfunction.