P1128

P1128 on a Toyota means the Throttle Control Motor Lock — the ECM commanded the throttle motor to move, monitored motor current and TPS feedback, and concluded the motor is mechanically locked or seized. The lock detection logic typically triggers when motor current is pinned at the H-bridge maximum (usually 3A or more) for longer than 500ms while TPS position fails to change by more than 2 degrees. The fallback behavior is the same as P1125: limp-home idle around 1,000-1,200 RPM with no real pedal response. Cheapest-first ladder: (1) inspect the throttle body bore and blade visually — a carbon ring on the leading edge of the blade or a chunk of carbon wedged against the bore wall is the mechanical lock in roughly 60% of cases. (2) With the throttle body off and the harness still connected (key off), try to move the blade by hand through its full 0-90 degree sweep; healthy ETCS-i blades move with light spring resistance only. If the blade binds at any angle, that's the lock. (3) Scan live commanded vs. actual TPS with motor current overlaid — if commanded jumps to 30 degrees, motor current spikes to 3A within 50ms, and actual TPS sits at 8 degrees, the motor is hitting a mechanical stop short of commanded position. Expensive-misdiagnosis caveat: a P1128 lock that comes back within 100 miles of a successful throttle-body clean usually means the motor itself has failed brush contacts, not a re-fouled bore — at that point the throttle body is the right call ($350-$500 part + ~30 min labor + relearn).

Vehicle-specific patterns: 2002-2009 Camry 2.4L (2AZ-FE) and 1997-2001 Camry 2.2L (5S-FE) are common P1128 platforms; the 2AZ-FE in particular has a long history of carbon-clogged throttle bores at 100K-130K mi. 2007-2017 Camry 3.5L (2GR-FE) and Solara 3.0L/3.3L (1MZ-FE, 3MZ-FE) throw P1128 with the same carbon-fouling timeline. 2008-2013 Highlander 3.5L (2GR-FE) and 2004-2007 Highlander 3.3L (3MZ-FE) throw P1128 alongside P1125 frequently — same root cause, different threshold crossing. 2006-2012 RAV4 with the 2AZ-FE or 2AR-FE 2.4/2.5L throws P1128 less often than P1125, but when it does the motor (not the bore) is more often the failed component. Estimated repair: $80 to $550.