Parts for your 1998 Daihatsu Gran move-Throttle position sensors

1998 Daihatsu Gran Move throttle position sensor (TPS): what it does and how to look after it

Technical sources confirm the 1998 Daihatsu Gran Move (also known as the Pyzar, G30-series) uses a throttle position sensor as part of its electronic fuel injection. References include: Daihatsu G30-series Pyzar/Gran Move Workshop Manual, Engine Control (EFI) section – component listing and test procedures for “Throttle Position Sensor”, Daihatsu Electronic Parts Catalogue (G30# Gran Move, Fuel System group) – part listing under “Sensor, Throttle Position”, and Haynes Charade & Gran Move (1987–2000) petrol Manual – EFI diagnostics covering TPS function and adjustment. With those sources, it’s clear a TPS is fitted and relevant to this model year.

On the 1998 Gran Move, the throttle position sensor tells the ECU exactly how far open the throttle is. That signal is used to fine‑tune fuel delivery, dial in ignition timing, manage decel fuel cut, and smooth out idle control. On autos, it also helps with kickdown and shift quality. In short, when the TPS is happy, the engine feels crisp off the line and throttle response is clean and predictable.

Signs the TPS needs attention can include a hesitant take‑off, flat spots on light throttle, hunting idle, a stubborn high idle after warm‑up, poor fuel economy, lazy kickdown on automatics, or a check‑engine light with TPS‑related fault codes. Because the unit is a wear‑type potentiometer on most Gran Moves, gradual drift or dead spots can appear with age.

Servicing is straightforward. The sensor lives on the throttle body, opposite the cable quadrant. Basic maintenance involves ensuring the connector is clean and the throttle body isn’t gummed up. For testing, a multimeter across the signal and earth pins should show roughly 0.4–0.7 V at closed throttle, rising smoothly to about 4.0–4.8 V at full throttle, with no dropouts. Any spikes or dead zones point to replacement.

When replacing, it pays to mark the old sensor’s position, swap the unit, then set the new one so the closed‑throttle voltage is in spec. Some versions also have an idle‑switch function that needs a small rotational adjustment—use a feeler gauge or the voltage method per the workshop manual. Use the correct JIS screwdriver for the mounting screws, nip them up lightly (they’re easy to strip), and don’t force the sensor’s tang on the throttle shaft. After refitting, clear any stored codes and let the ECU relearn at idle with all loads off. Keeping the air intake clean and checking the harness for brittle insulation will help the TPS and idle control motor live a long, drama‑free life.

• Typical closed‑throttle signal: 0.4–0.7 V
• Typical wide‑open throttle signal: 4.0–4.8 V
• Common symptoms of faults: hesitation, hunting idle, poor kickdown, ECU fault codes

Technical sources referenced: Daihatsu G30‑series Pyzar/Gran Move Workshop Manual (EFI/TPS test and adjustment), Daihatsu Electronic Parts Catalogue (G30# Gran Move, Fuel System – Sensor, Throttle Position), Haynes Charade & Gran Move (1987–2000) petrol Manual – EFI diagnostics and sensor checks.

Popular questions

Where is the TPS on a 1998 Daihatsu Gran Move?
The TPS is mounted on the throttle body, opposite the throttle cable linkage. It’s a small plastic sensor with a 3‑pin plug. Looking from the front of the engine bay, find the air intake duct, then the throttle body— the TPS sits on the side with two small screws holding it on.

How do you test the TPS at home?
Back‑probe the signal and earth pins with a multimeter. Key on, engine off, watch the voltage rise smoothly from around 0.4–0.7 V at closed throttle to about 4.0–4.8 V at full throttle. Any jumps, dead spots, or readings outside spec suggest the sensor or its wiring needs attention.

Does a new TPS need calibration?
Yes, a light rotational adjustment is usually required so closed‑throttle voltage lands in spec and the idle switch (if present) toggles correctly. Loosen the screws, rotate slightly, tighten, and recheck voltage. Final confirmation is a stable warm idle and clean throttle response on a short road test.