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OBD-II Code

P1128

Severity

Not yet reviewed

Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.

Can you drive it

We cannot say

Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.

Indicative cost (USD)

$80–$550

From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.

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.

How a shop works this

Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.

  1. Note every code that is set, not just this one.

    Codes that appear together usually narrow the cause faster than any one of them read alone.

  2. Read the freeze frame — the conditions the fault was recorded under.

    Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.

  3. Confirm the fault is current rather than history.

    Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.

  4. Then follow the diagnostic notes further down this page, in the order they are written.

    They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.

If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.

Common symptoms

  • Check engine light
Read the full diagnostic procedureP1128 on a Toyota means the Throttle Control Motor Lock — the ECM commanded the throttle motor to move, monitored motor current and TPS feedback, and…

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 patterns2002-2009 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-clog…
  • 2002-2009Camry 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.
  • 2007-2017Camry 3.5L (2GR-FE) and Solara 3.0L/3.3L (1MZ-FE, 3MZ-FE) throw P1128 with the same carbon-fouling timeline.
  • 2008-2013Highlander 3.5L (2GR-FE) and 2004-2007 Highlander 3.3L (3MZ-FE) throw P1128 alongside P1125 frequently — same root cause, different threshold crossing.
  • 2006-2012RAV4 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.

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