Parts for your 2003 Toyota Caldina-Throttle position sensors

2003 Toyota Caldina throttle position sensor (TPS): what it does and how to look after it

Yes, the 2003 Toyota Caldina uses a throttle position sensor. Technical sources including the Toyota Electrical Wiring Diagrams (EWD) for Caldina 2002–2005, Toyota Repair Manuals for the 1AZ-FSE/1ZZ-FE SFI systems, and the ST246 3S-GTE ETCS‑i engine control documentation all specify throttle angle feedback to the ECU via a TPS. On the 1AZ-FSE and ST246 3S-GTE models, the TPS is integrated into the electronic throttle body (ETCS‑i) with dual signals (VTA/VTA2). On some 1ZZ-FE cable-throttle variants, a separate, adjustable TPS is fitted to the throttle body.

The TPS tells the engine computer exactly how far the throttle plate is open, so fuelling, ignition timing, and transmission shift strategy (on autos) can be spot on. It’s a core signal for cold starts, smooth take-off, steady cruise, and snappy response when the pedal’s prodded. On ETCS‑i models, the ECU also compares the TPS to the accelerator pedal position sensor to keep everything safe and tidy under the bonnet.

For servicing, the approach depends on which Caldina engine’s under the bonnet. On 1AZ-FSE and ST246 3S-GTE, the TPS is part of the throttle body and generally isn’t serviced separately, if the sensor fails, the throttle body assembly is replaced, followed by an idle/ETCS learning procedure with a scan tool. Keeping the throttle bore clean (without flooding the shaft area) and ensuring the connector pins are clean and snug goes a long way to happy kilometres. On 1ZZ-FE cable-throttle cars, the TPS can usually be replaced on its own. Correct alignment is important—fit the new sensor, set it to spec using a scan tool (watching VTA at closed throttle) or the service data, then check for smooth, glitch-free voltage rise as the throttle opens.

• Common signs it’s grumpy: erratic idle, flat spots, harsh shifts, poor fuel economy, or limp-home with the MIL on.
• Typical DTCs you might see: P0120–P0123, P0220–P0223, or correlation faults on ETCS‑i.
• Best practice: inspect the harness for rub-through, verify a clean 5 V reference and ground, and confirm stable TPS signals in live data.

Replacement tips: use quality parts, don’t overtighten mounting screws, and on ETCS‑i always perform throttle/idle relearn after any throttle body work. A quick check during routine servicing—clean throttle, inspect connector, scan for pending codes—keeps the Caldina behaving as it should.

Does the 2003 Toyota Caldina have a TPS?

It does. All 2003 Caldina engines provide throttle angle feedback to the ECU. The 1AZ-FSE and ST246 3S-GTE use an integrated TPS in the ETCS‑i throttle body, while some 1ZZ-FE variants use a separate, adjustable TPS on a cable throttle body.

What symptoms point to a failing TPS on a Caldina?

Drivers often notice a hunting idle, hesitation off the line, odd kick-down or harsh shifts, and increased fuel use. The check engine light may appear with codes like P0120–P0123. Live data will usually show glitches or mismatched VTA/VTA2 on ETCS‑i systems.

Can a TPS be cleaned or reset, or does it need replacing?

The sensor itself isn’t a cleaning item. Clean the throttle bore to prevent sticking, but avoid soaking the shaft area. On ETCS‑i models, faults usually mean replacing the throttle body assembly, then running the throttle/idle relearn. On cable-throttle 1ZZ-FE cars, a standalone TPS can be replaced and adjusted to spec.