P0223
Throttle/Pedal Position Sensor/Switch B Circuit High Input
When a vehicle powertrain module registers the fault code P0223, it points directly to an internal system malfunction identified as "Throttle/Pedal Position Sensor/Switch B Circuit High Input". Operating your engine under this condition may degrade long-term fuel maps.
Driver's Summary
When your OBD2 scanner shows P0223, the engine control module has flagged an issue specifically related to throttle/pedal position sensor/switch b circuit high input. In practice, this fault causes high idle, unresponsiveness to gas pedal, mil illuminated. Stop driving as soon as it is safe to do so. This fault can lead to expensive secondary damage if left unaddressed.
Symptoms
High idle, unresponsiveness to gas pedal, MIL illuminated
Common Causes
- Short to battery voltage in TPS circuit
- Broken sensor ground wire
- Failed Throttle Position Sensor
- Bad PCM
How to Fix
- 1 Trace and repair short circuit
- 2 Repair broken ground wire
- 3 Replace TPS sensor
- 4 Replace PCM
Technical Explanation
The ECM detects code P0223 by continuously monitoring the relevant sensor circuit against calibrated threshold values stored in its non-volatile memory. The PCM monitors crankshaft rotational velocity via the CKP sensor at a resolution of individual tooth gaps on the reluctor ring. A combustion event in each cylinder produces a measurable acceleration spike; its absence or weakness is flagged as a misfire event within a 200-revolution or 1000-revolution test window. The fault remains stored in memory even after the MIL is cleared; it becomes a confirmed DTC after failing two consecutive drive cycles, and the PCM logs a freeze frame record of the engine's exact operating state at the moment of detection.
Is It Safe to Drive?
An active P0223 code under high-severity conditions means the affected system is operating outside safe parameters. Continued driving — especially under load or at highway speeds — significantly increases the risk of secondary damage to components like broken sensor ground wire.
Mechanic's Pro Tip
Module replacement should always be the last resort for P0223 after exhaustively verifying all power supply circuits, ground connections, and communication bus wiring. Use a wiring diagram to locate all fuses, relays, and ground points for the affected module, and measure voltage drop on each ground with the circuit loaded. A module "failure" is frequently a corroded ground eyelet or a weak battery causing brownout conditions — fix these first and you'll save hundreds of dollars on an unnecessary module replacement.
Wiring repair: $100 - $200; TPS: $100 - $300