P2128 OBDII diagnostic code means that the PCM (Powertrain Control Module) has encountered a high voltage in either the TPS (Throttle Position Sensor) or PPS (Pedal Position Sensor) circuit. The “E” designation mentioned in this code refers to a particular circuit or area of the sensor. For this reason, you should consult a vehicle information source.
The PCM is responsible for controlling the Drive-By-Wire (DBW) system, by means of a throttle motor actuator and Throttle Position Sensors. These sensors receive 5 volts reference volts along with a ground signal.