Parts for your 2007 Toyota Ist-Throttle position sensors

2007 Toyota ist throttle position sensors: what they do and how to look after them

Technical references confirm the 2007 Toyota ist does use throttle position sensors. Toyota’s ETCS‑i system description in the NCP110/NCP115 repair manual outlines an electronic throttle body with a built‑in dual TPS (often referred to as VTA1/VTA2) that reports throttle angle to the ECM. The model’s Electrical Wiring Diagram shows the TPS circuits (VC, VTA1, VTA2, E2), and factory diagnostics include DTCs P0120–P0124 for TPS range and performance faults. Platform cousins—the Scion xD and Toyota Urban Cruiser—share the same throttle body architecture, supporting the fitment on the 2007 ist.

On this ist, the throttle position sensors sit inside the throttle body with the throttle actuator motor. Their job is to tell the engine computer exactly how far the throttle plate is open so it can match air, fuel, and spark for smooth take‑off, tidy idle, and decent economy. With ETCS‑i there are two sensor tracks for redundancy, so the ECM can cross‑check signals and head off erratic behaviour if one track goes noisy.

As part of service, it’s smart to keep the throttle body clean. Light carbon on the plate and bore can make the TPS readings appear out of whack at tiny openings, nudging idle speed up or causing a stumble. Use throttle‑body‑safe cleaner and a lint‑free cloth, and avoid soaking the motor or the sensor housing. Don’t touch the factory stop screw—there’s no manual adjustment on this setup.

If the TPS sets a fault or data looks off on a scan tool, replacement usually means swapping the entire throttle body assembly because the sensor is integral on most 2007 ist engines. After refit—or after a battery disconnect or heavy clean—perform an idle/throttle learning routine. Many scan tools have a guided procedure, otherwise, follow the Toyota repair manual steps. Signs that point to TPS trouble include:

• Hunting or high idle, poor tip‑in, or flat spots
• Fuel use creeping up, or harsh shifts on autos
• Check engine light with TPS‑related DTCs

Use new gasket, check for air leaks, and verify live data (APP vs. throttle angle) after any work. Genuine‑spec parts and correct relearn save headaches down the track.

Popular questions about 2007 Toyota ist throttle position sensors

Does the 2007 Toyota ist have a separate, replaceable TPS?
Most 2007 ist variants use an electronic throttle body with the TPS built in. In those cases, the sensor isn’t sold separately and the complete throttle body is replaced if the TPS fails. Always confirm by VIN against the parts catalogue, as hardware can vary by engine code and market.

What are common signs of a failing TPS on this model?
Typical clues include erratic or high idle, hesitation on light throttle, flat spots, and increased fuel use. The check engine light may set with codes like P0121 or P0122. A scan tool will usually show mismatched or jumpy throttle angle data compared to accelerator pedal input.

Is a throttle body relearn needed after cleaning or replacement?
Yes. After cleaning, battery disconnect, or fitting a new throttle body, perform the throttle/idle learning procedure outlined in the Toyota repair manual or via a capable scan tool. Skipping the relearn can leave the idle unstable or the throttle response inconsistent.