Parts for your 2005 Toyota Prius-Throttle position sensors

2005 Toyota Prius throttle position sensor (TPS): what it does and how to look after it

Yes, the 2005 Toyota Prius does use throttle position sensing. On the second‑gen Prius (NHW20, 2004–2009) it’s part of Toyota’s ETCS‑i electronic throttle body, where a dual‑track throttle position sensor is built into the throttle body assembly rather than sold as a separate, bolt‑on sensor. Technical references that confirm this include the Toyota Repair Manual for 2004–2009 Prius (NHW20) sections covering ETCS‑i and “Throttle Body with Motor,” the Toyota Electrical Wiring Diagram (EWD) that shows the VTA1/VTA2 throttle position circuits to the ECM, and the Prius OBD‑II diagnostics for DTCs P0120–P0124 and P2135, which specifically monitor throttle position and correlation.

On a 2005 Prius, the throttle position sensor’s job is to tell the engine control module exactly where the throttle plate is, so it can match airflow to the requested torque from the accelerator pedal and the hybrid system. Because the car is drive‑by‑wire, the ECM uses both the accelerator pedal position sensors and the throttle position sensors to keep everything tidy and safe. If they disagree, the car will protect itself with reduced power or a fault light. That’s why clean, reliable throttle feedback matters even on a hybrid that stops and starts the engine a lot.

Servicing is straightforward. The TPS itself isn’t separately replaceable, if the sensor fails or its signals go out of range, the fix is typically a new or quality remanufactured throttle body assembly with a fresh gasket. Before jumping to replacement, a good workshop will scan live data to check VTA1/VTA2 tracking, look for correlation faults like P2135, and inspect the loom and connector for damage or corrosion.

Prevention is better than cure. Every 80–100,000 km (or if there’s rough idle, stalling at start‑up, or surging), it’s wise to have the throttle body cleaned. With the ignition off, remove the intake duct and gently clean the throttle bore and plate using throttle‑body‑safe cleaner and a lint‑free cloth—no forcing the plate by hand, and no soaking the electronics. After cleaning or replacement, clear any stored codes and let the ECM relearn by allowing the engine to reach operating temp and settle, the Prius will self‑adapt without a manual calibration step.

If replacement is needed, stick with the correct NHW20‑spec throttle body, swap the gasket, torque the fasteners to spec, and double‑check for vacuum leaks. A quick road test while watching live data will confirm the throttle position tracks smoothly with pedal input—sweet as.

• Technical references: Toyota Repair Manual (NHW20, ETCS‑i/Throttle Body with Motor), Toyota EWD (VTA1/VTA2 circuits), OBD‑II DTCs P0120–P0124, P2135.

Popular questions

Does a 2005 Prius have a throttle position sensor?
It does. The TPS is integrated into the electronic throttle body as part of ETCS‑i, so it’s not sold as a separate little sensor. If it fails, the usual remedy is replacing the throttle body assembly.

What are the signs the TPS/throttle body is playing up on a 2005 Prius?
Common clues include a check engine light, limp‑home behaviour, poor response to the pedal, rough idle on engine start, or codes like P0120–P0124 or P2135. A scan tool will show erratic or mismatched VTA1/VTA2 signals if the sensor is crook.

Can the TPS be cleaned or recalibrated on a 2005 Prius?
You can clean the throttle body to remove gunk that affects movement, but the TPS itself isn’t serviceable. There’s no separate calibration, the ECM relearns after cleaning or replacement. Clear codes and let it idle to operating temperature so it can adapt.