What Does Code P0228 Mean? The OBD-II diagnostic trouble code P0228 signifies an issue with the “C” circuit of the Throttle Position Sensor (TPS) or Accelerator Pedal Position Sensor (APPS), indicating a High Input condition. In modern drive-by-wire (DBW) systems, the Engine Control Module (ECM) or Powertrain Control Module (PCM) relies on these sensors to […]