Parts for your 2017 Lexus Is-Throttle position sensors

2017 Lexus IS throttle position sensor (TPS): what it does and how to look after it

Technical documentation for the 2017 Lexus IS range (Lexus/Toyota TIS Repair Manual, New Car Features and EWD) confirms the cars use electronic throttle control (ETCS‑i) with throttle position sensors built into the throttle body. This covers IS200t/IS300 (8AR‑FTS 2.0‑litre turbo), IS350 (2GR‑FKS V6) and IS300h (2AR‑FSE hybrid). The ECM monitors the throttle opening via dual TPS circuits and flags faults with DTCs such as P0120–P0124, P0220–P0222 and P2135, so the TPS is definitely fitted and relevant on the 2017 Lexus IS.

On these models the TPS tells the engine computer exactly how far the throttle plate is open, so fuelling, ignition timing and transmission behaviour stay smooth. It works alongside the accelerator pedal position sensor (APPS) and the throttle actuator motor, giving precise, drive‑by‑wire control with built‑in redundancy for safety.

Because the TPS is integrated into the throttle body, it’s not a separate service item. During regular servicing, a good workshop will:

• Scan for stored or pending TPS‑related codes and check live data for agreement between TPS 1/2 and APPS 1/2.
• Inspect the throttle body for carbon build‑up and clean the bore and plate with the correct throttle cleaner if needed.
• Perform an ETCS/throttle learn procedure after cleaning or battery disconnection so idle and tip‑in feel are stable.

Tell‑tale signs of a TPS issue include erratic idle, hesitation off the line, poor economy, cruise control dropping out, or the car going into limp mode with the MIL on. If diagnostics confirm a TPS fault or correlation error (for example P2135), the fix is typically replacement of the throttle body assembly. Given the calibration and safety functions involved, using a quality OEM or OE‑equivalent unit is the safe bet.

Cleaning can help drivability if the throttle plate is gummed up, but it won’t repair a failing sensor. Avoid forcing the plate open by hand, let the motor move it, and never soak the assembly. After any work, a scan tool procedure to initialise the throttle and clear adaptations is recommended, though a controlled warm‑up and idle relearn can suffice in a pinch.

For owners in Australia and New Zealand, TPS checks are best bundled with major services or when symptoms appear. Staying on top of it keeps the IS’s smooth, responsive character intact and prevents nuisance limp‑home episodes.

Popular questions

Does the 2017 Lexus IS have a throttle position sensor, even though it’s drive‑by‑wire?
Yes. The 2017 IS uses ETCS‑i, which includes dual throttle position sensors inside the throttle body and dual accelerator pedal sensors. The ECM cross‑checks them for accuracy and safety.

What fault codes point to a TPS problem on a 2017 Lexus IS?
Common codes include P0120–P0124 (TPS circuit range/performance), P0220–P0222 (TPS 2 circuit) and P2135 (throttle/pedal correlation). These indicate the ECM has seen an implausible signal or mismatch between the redundant sensors.

Can the TPS be cleaned or adjusted, or does it need replacing?
The TPS isn’t adjustable and is part of the throttle body. Cleaning the throttle bore helps sticky throttle symptoms but won’t fix a faulty sensor. If diagnostics confirm a TPS fault, replace the throttle body and perform a throttle relearn.