Parts for your 2006 Toyota Prius-Throttle position sensors

2006 Toyota Prius throttle position sensor: what it does, how it’s serviced, and when to replace

Yes, the 2006 Toyota Prius does use a throttle position sensor (TPS). Toyota’s own technical literature describes the NHW20 Prius throttle body as an ETCS-i unit (electronic throttle control with intelligence) that integrates a throttle motor and dual throttle position sensors. See Toyota Repair Manual coverage for the 1NZ-FXE Engine Control System (ETCS-i “Throttle Body with Motor and Sensor”) and the New Car Features (NCF) manual for Prius (ETCS-i overview). Relevant diagnostic trouble codes for this model include P0121, P0122, P0123 and P2135, all of which reference throttle/throttle position sensor circuits.

On a 2006 Prius, the TPS tells the engine control module the exact angle of the throttle plate. Because the car is drive-by-wire, the accelerator pedal position sensor reports the driver’s request, while the ECM commands the throttle motor to open or close the plate. The TPS then confirms the plate’s actual position. This closed-loop setup keeps the hybrid smooth, efficient, and safe, with twin sensor tracks providing redundancy.

There’s no scheduled replacement interval for the TPS on this model. It’s built into the throttle body, so if the sensor fails, the usual fix is replacing the whole throttle body assembly. During regular servicing, techs typically:

• Scan for DTCs and check live data (VTA1/VTA2 agreement, throttle angle, and correlation with accelerator input).
• Inspect the throttle body for carbon build-up and clean the bore and plate with appropriate throttle cleaner (battery off, no forcing the plate).
• Check wiring and connectors for corrosion, pin tension, or rodent damage.

Typical symptoms of a dodgy TPS include the MIL on, reduced power/limp behaviour, hunting idle when the engine is running, poor response, or surging. If any of these show up alongside the listed codes, plan on testing the circuit and, if confirmed, fitting a new throttle body.

After replacement, use a capable scan tool (Techstream or equivalent) to run the ETCS-i/throttle closed-position initialisation so the ECM learns the new unit. A 12‑volt battery reset can prompt relearning, but the proper utility is the reliable approach. Always use a quality gasket, torque fasteners correctly, and verify hybrid cooling fans are unobstructed before road testing. With clean throttle hardware and a healthy TPS signal, the Prius delivers the crisp, efficient drive it’s known for across Aussie and Kiwi roads.

Popular questions

Does the 2006 Prius actually have a throttle position sensor?
Yes. It uses an electronic throttle body that includes dual throttle position sensors. This is separate from the accelerator pedal position sensor at the pedal. The ECM compares both throttle sensor signals for accuracy and safety.

What symptoms point to a failing TPS on a 2006 Prius?
Common signs are a check engine light, sluggish acceleration, limp mode, irregular idle when the engine is on, or surging. Scan for codes such as P0121–P0123 or P2135 and check live data for disagreement between the two TPS tracks.

Can the TPS be cleaned or must it be replaced?
The TPS itself isn’t serviceable separately, it’s part of the throttle body. Cleaning carbon from the throttle plate can help drivability, but if the TPS is faulty, replace the throttle body and perform the ETCS-i initialisation with a suitable scan tool.