P2105

P2105 is the most aggressive throttle code in the TAC family — the ECM has commanded a forced engine shutdown because it detected a fault so severe that running the engine at all is judged unsafe. This is usually thrown when the throttle blade is reading wide-open while the pedal reads closed, when both TPS sensors disagree by more than 30%, or when the motor is drawing massive current trying to move a seized blade. The car will start, run for a few seconds, then shut down on its own; restart attempts will repeat the same cycle. Cheapest-first is misleading here because P2105 means something is mechanically wrong — but you still start with the visual: pop the throttle body off and inspect for a bent blade, a broken return spring, debris jammed in the bore, or a chunk of intake snorkel sucked in. Clean it only if it's reusable. Backprobe both TPS signals against ground and verify they sweep opposite directions through the full blade range; backprobe both APP signals at the pedal and verify the same. If either pair is correlated wrong (both going the same direction, or one stuck flat), the sensor or harness is the fault.

Vehicle-specific patterns: 2007-2011 Toyota Camry / RAV4 with the 2AR-FE 2.5L is the famous P2105 vehicle — this is the unintended-acceleration recall era, and Toyota's response was an aggressive forced-shutdown threshold; pedal-position sensor mat interference (the all-weather floor mat trapping the pedal) and worn pedal-sensor wipers both trigger P2105, and the recall remedy was a redesigned pedal assembly. 2005-2010 VW Jetta / Passat / Audi A4 2.0T (BPY, BWT) sees P2105 from internal throttle-body failures where the motor housing cracks and lets the blade flop free of the gear train. 2008-2014 Dodge Caravan / Town & Country 3.6L Pentastar throws P2105 from a known wire-chafe in the throttle harness where it routes over the intake manifold. Critical: P2105 is the one throttle code where you should not just clear-and-drive — verify the throttle body moves freely by hand with the connector unplugged, verify both sensor pairs track correctly on a scope, and run the relearn before returning the car to the customer. A misdiagnosed P2105 is a runaway-engine lawsuit.