P0223

P0223 indicates TPS sensor B signal voltage exceeded the upper limit (typically above 4.80 V) for the persistence window, pointing to a short to voltage, an open ground inside the sensor, or a complete sensor failure where the wiper has lost contact. Cheapest first: backprobe TPS-B signal at the connector key-on — if it reads pinned at or near 5 V with the throttle closed (where it should read ~4.5 V on inverted-track platforms or ~0.5 V on direct-track platforms), confirm the sensor ground at the connector with a voltage drop test (under 100 mV to battery negative under load). Disconnect the sensor: if the signal wire still reads 5 V at the harness side, you have a short to the 5 V reference somewhere in the harness, not a bad sensor. If the harness side reads 0 V with the sensor unplugged, plug it back in and the high reading returns, the sensor is open internally. Caveat: on GM ETC trucks, carbon on the throttle plate can prevent the plate from fully closing, leaving TPS-B reading higher than the learned closed value at idle — induction clean plus relearn before swapping the throttle body.

Vehicle-specific patterns: 2007-2014 GM 5.3L/6.2L (LC9/L94/L9H) — carbon buildup on throttle plate keeps it cracked open at rest, TPS-B reads high at idle; throttle body cleaning plus idle/ETC relearn fixes it without replacement. 2005-2010 Honda Accord/Odyssey 3.5L (J35) — integrated TPS internal open, ETB assembly replacement is the only path (no separate sensor). 2007-2013 Nissan Frontier/Xterra 4.0L (VQ40DE) — TSB NTB08-016 covers ETB part 16119-EA000 for repeated P0223. 2006-2012 Ford Escape 3.0L Duratec — sensor ground open at the PCM connector C175 pin 31, repair pin tension before replacing throttle body. Estimated repair: $90 to $600.