Parts for your 2003 Toyota Kluger-Throttle position sensors

2003 Toyota Kluger throttle-position-sensors: what they do and how to look after them

Yes, the 2003 Toyota Kluger does use throttle-position-sensors (TPS). Toyota’s own technical literature for the first‑gen Kluger/Highlander (ACU20/MCU25) shows the engine management uses ETCS‑i (Electronic Throttle Control) with dual throttle position signals (often labelled VTA1/VTA2) sent to the engine ECU from the throttle body assembly. This is covered in the Toyota Repair Manual sections for the SFI/ETCS‑i system and the DTC list that includes TPS‑related faults (for example P0120–P0124, P2135). Toyota’s parts catalogue for these models also lists the throttle body assembly with an integrated TPS for both the 2AZ‑FE 2.4‑litre and 1MZ‑FE 3.0‑litre engines, with the sensor typically not serviced separately.

On this Kluger, the throttle-position-sensors tell the ECU exactly where the throttle plate sits. Paired with the accelerator pedal position sensor, the ECU uses the TPS feedback to control airflow, fuel, and ignition timing for smooth take‑off, decent fuel economy, and clean emissions. Because it’s drive‑by‑wire, there are usually two TPS circuits in the throttle body for redundancy and safety.

• Common hints the TPS circuit is unhappy: sluggish take‑off, random surging, erratic idle, poor fuel economy, harsh shifts, limp‑home behaviour, and the check engine light with codes like P0120–P0124 or P2135.

There’s no scheduled replacement for the TPS on a 2003 Kluger, but as part of routine servicing it’s smart to keep the throttle body clean and the TPS connector tidy. A dirty throttle bore or sticky plate can mimic a failing sensor. During a service, a quick visual on the loom and connector, plus a scan of live data for matching VTA1/VTA2 signals and smooth throttle sweep, goes a long way.

If the TPS is integrated (as it is on most 2003 Klugers), replacement usually means fitting a new throttle body assembly with a fresh gasket. The job is straightforward: battery off, intake duct off, coolant hoses (if fitted) and connector off, swap the body, then perform an idle/throttle relearn with a capable scan tool (Toyota Techstream is ideal) and check for air leaks. If your variant has a separate TPS, it can be replaced on the throttle shaft and set per the repair manual spec, but that’s less common on this model year.

As a rule of thumb, inspect and clean the throttle body every 40,000–60,000 km, especially if most driving is around town. Keeping the air filter fresh and the battery/charging system healthy also helps TPS behaviour and ETCS‑i stability.

• How do you know if the TPS on a 2003 Kluger is failing?

Drivers usually notice a check engine light and drivability niggles like hesitation, hunting idle or sudden loss of power. A scan tool will often show codes P0120–P0124 or P2135. Watching the live data, the two throttle angle signals should rise and fall smoothly and track each other—flat spots or mismatch point to a TPS/throttle body issue.

• Can the TPS on this model be cleaned instead of replaced?

The sensor itself isn’t serviceable, but cleaning the throttle bore and plate can restore proper movement and signal stability if grime is the culprit. If the internal sensor tracks are worn or the signals disagree, the fix is replacement of the throttle body assembly and a throttle relearn.

• Do you need to recalibrate after replacing the throttle body?

Yes. After swapping the throttle body, perform an idle and throttle position relearn with a suitable scan tool and confirm there are no intake leaks. Without the relearn, idle quality and throttle response can be ordinary until the ECU adapts—if it adapts at all.