Parts for your 2014 Lexus Is-Throttle position sensors

2014 Lexus IS throttle position sensors: what they do and how to look after them

Based on Lexus/Toyota technical literature (Lexus IS Repair Manual for the GSE30/31/35 and AVE30 series, ETCS‑i coverage in New Car Features, and diagnostic coverage for DTCs P0120–P0124, P2135), the 2014 Lexus IS does use throttle position sensors. They’re built into the electronic throttle body as dual, redundant sensors that report the throttle plate angle to the engine ECU. This applies to the IS 250, IS 350 and the IS 300h hybrid. There’s also a separate accelerator pedal position sensor, the ECU cross‑checks both for safety and accuracy.

The throttle position sensors (TPS) tell the ECU exactly how far the throttle blade is open, so fuel, spark, idle speed, transmission shift strategy, traction control and cruise control all behave as intended. On these drive‑by‑wire cars, the TPS works hand‑in‑hand with the pedal sensor and the throttle actuator motor, if the readings disagree, the ECU can drop the car into limp mode to protect the engine and driveline.

• Common signs of TPS trouble: check engine light, rough or hunting idle, flat spots or surging on light throttle, poor fuel economy, harsh shifts, and reduced power/limp mode.
• Typical fault codes: P0120–P0124 (TPS circuit range/performance) and P2135 (correlation between throttle and pedal sensors), as noted in Lexus diagnostics.

There’s no routine replacement interval for the TPS, it’s a sealed, non‑wear electronic component within the throttle body. As part of regular servicing, it’s smart to keep the intake tract clean and the throttle bore free from heavy deposits. Use a proper throttle body cleaner, avoid forcing the blade open by hand, and don’t drown the electronics. If the throttle body is removed, fit a new gasket and tighten the fasteners evenly.

If diagnostics point to a TPS fault, many workshop manuals and parts catalogues show it as part of the throttle body assembly. On some variants a TPS sub‑assembly may be listed, but in practice the whole throttle body is often replaced to ensure correct calibration and reliability. After any replacement or a thorough clean, perform the throttle/idle learn procedure with a scan tool so the ECU relearns the blade position. Clear codes, road‑test, and verify live data shows smooth, linear throttle angle change with pedal input.

1. Scan for codes and view live data (throttle angle, pedal position, correlation).
2. Inspect connectors and wiring, check for water ingress or pin tension issues.
3. Clean the throttle body if dirty, then carry out an idle/throttle relearn.
4. If faults persist, replace the throttle body (or TPS sub‑assembly where applicable) and initialise per Lexus procedure.

Using quality parts and following the Lexus service steps keeps the 2014 IS crisp on throttle and drama‑free on the daily commute.

FAQs

Does the 2014 Lexus IS have a throttle position sensor or only a pedal sensor?
Yes. It has both. The throttle position sensors are built into the throttle body (two sensors for redundancy), and there’s a separate accelerator pedal position sensor. The ECU compares them for accuracy.

Can the TPS be replaced separately, or is it a full throttle body job?
On many 2014 IS variants, the TPS is integrated and serviced with the throttle body. Some parts listings show a TPS sub‑assembly, but most workshops replace the complete throttle body to avoid calibration and reliability issues.

How often should the throttle body be cleaned on a 2014 IS?
There’s no strict interval, but every 40–60,000 km or when idle quality drops is a fair rule of thumb. Use throttle‑safe cleaner, don’t lever the blade, and perform a throttle/idle relearn afterwards.