Parts for your 1993 Toyota Caldina-Throttle position sensors

1993 Toyota Caldina throttle position sensor (TPS) — what it does and how to look after it

Yes, the 1993 Toyota Caldina is fitted with a throttle position sensor. Toyota’s own technical literature for the 3S-FE and 4S-FE engines (TCCS EFI systems as shown in Toyota Repair Manuals of the era) specifies a TPS with IDL and VTA circuits on the throttle body, and the Toyota Electronic Parts Catalogue (T190-series Caldina, 1992–1997) lists a “Sensor, Throttle Position” for these engines. Diagnostic procedures in Toyota service manuals also reference OBD1 fault code 41 for TPS signal issues. So it’s definitely used on this model and it matters for smooth running.

The TPS tells the engine ECU exactly how far the throttle plate is open. That signal helps the ECU sort fuelling and ignition timing, cut fuel on decel, control idle speed, manage EGR, and, on autos, fine-tune shift timing and line pressure. In short, it’s a small part that has a big say in how the Caldina behaves from take-off to motorway cruising.

When a TPS starts to go flaky, owners may notice flat spots off the line, hunting idle, a surge at light throttle, harsh or late shifts on auto models, or worse fuel economy. The check-engine light may log a code 41 (TPS signal). Quick checks under the bonnet with a multimeter can save guesswork:

• Back-probe VTA to E2 (ignition ON): around 0.4–0.8 V closed throttle, rising smoothly to roughly 3.7–4.5 V at wide-open throttle, with no dead spots.
• IDL switch: continuity to E2 at closed throttle, opening as the plate just cracks open.

Replacement is straightforward with basic tools. Under the intake duct sits the TPS on the throttle body, held by two small screws. Mark the old sensor’s position, unplug the connector, and swap it over. The key is the set-up: rotate the new sensor so the idle (IDL) switch is closed at rest and opens right as the throttle first moves. Toyota procedures often specify using a thin feeler gauge at the stop to confirm this. Nip the screws up firmly (they’re small, don’t go gorilla on them), refit the intake tube, clear the ECU’s memory (EFI fuse or battery off for a minute), then let the engine idle to settle.

Helpful habits: keep the throttle body clean, but avoid flooding the TPS with solvent. Make sure the connector is clean and dry, a dab of dielectric grease on the seal helps in wet Kiwi and Aussie conditions. Sticking with a quality (often Denso) sensor pays off over cheap copies, especially on higher-kilometre cars.

Popular questions about 1993 Toyota Caldina TPS

Where is the TPS on a 1993 Caldina?
The TPS sits on the side of the throttle body, opposite the throttle cable wheel. It’s a small black plastic unit with a 3- or 4-pin connector. On most 3S-FE and 4S-FE setups, it’s easy to spot once the air intake duct is off.

What fault code points to a TPS issue on this model?
Toyota’s OBD1 code 41 indicates a TPS signal fault. Owners can bridge TE1 and E1 in the diagnostics connector under the bonnet and count the flashes of the check-engine light. If 41 shows up, check connector pins, wiring continuity, and the sensor’s voltage sweep before replacing parts.

Does a new TPS need calibration?
Yes. After fitting, the TPS needs to be adjusted so the idle switch is closed at rest and opens just as the throttle starts to move. This can be set using a feeler gauge at the throttle stop or by monitoring voltage and switch continuity. Correct calibration avoids wonky idle and shift quality.