P2105: Throttle Actuator Control System — Forced Engine Shutdown
Do not keep driving
If this happens while you are moving: keep hold of the wheel — the steering will suddenly become very heavy but it still works — brake firmly and progressively rather than pumping the pedal, since the assistance you have left is limited, and get the vehicle off the road. Do not attempt to restart while moving.
Afterwards, have it recovered rather than restarted and driven. And ask what other codes are stored: this one records that the engine was shut down, not why, and the reason is in the same list.
What this code means
The module has shut the engine down. This is the most severe step of the graded response described under P2104, and it is reserved for the case where the system concludes it can no longer be sure what the throttle is doing.
Stopping an engine is a drastic thing for a control module to do, and it is the correct thing when the alternative is an unpredictable throttle. But it carries its own hazard, and the page would be dishonest not to say so: an engine that stops while the vehicle is moving takes power steering and brake assistance with it. The brakes still work — there is enough vacuum stored for a few applications, and the mechanical linkage is unaffected — but they become very much heavier, and the steering becomes heavy immediately. At speed that is a genuine emergency rather than an inconvenience.
So the driver advice here is not really about diagnosis. It is about what to do in the moment.
As with the rest of the forced family, this code names the response and not the cause. The actual fault is stored alongside it.
Likely causes
Start here
- Fault in the throttle position sensors · moderate
- Fault in the accelerator pedal position sensors · moderate
Less common
- Throttle plate stuck open · moderate
- Failed sensor reference voltage supply · moderate
- Faulty engine control module · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about P2105.