Parts for your 1999 Daihatsu Gran move-Throttle position sensors

1999 Daihatsu Gran Move Throttle Position Sensor (TPS): What it does and how to look after it

Yes — the 1999 Daihatsu Gran Move (also known as the Pyzar G3-series) uses a throttle position sensor. This is confirmed in the Daihatsu Pyzar/Gran Move G3 Workshop Manual (Engine Control/EFI section), which shows the TPS on the throttle body with ECU pins for VC (5 V reference), VTA (signal), E2 (earth), and an IDL closed-throttle contact. The same arrangement is covered in Daihatsu HC-EJ engine technical training material and Denso EFI diagnostic flowcharts used on late‑90s Daihatsu models. It’s a standard part of the electronic fuel injection system on the 1.5-litre HC‑EJ engine fitted to the Gran Move around 1999.

On this model, the TPS tells the ECU exactly how far the throttle is open. That signal helps the ECU sort fuelling, ignition timing, idle control and, on autos, shift behaviour. When the sensor starts to drift or glitch, the Gran Move can feel doughy off the mark, surge, hunt at idle, or kick up a check light with codes like P0120–P0123 on compatible scan tools.

Servicing-wise, the TPS doesn’t need regular replacement, but it does benefit from periodic checks. Every 40,000–60,000 km, it’s smart to inspect the connector for green corrosion, make sure the wiring has good strain relief, and verify that a scan tool shows a smooth throttle percentage from closed to wide open. With a multimeter back-probed on VTA to E2, expect roughly 0.45–0.7 V at closed throttle, rising smoothly to around 4.2–4.7 V at full throttle. Any flat spots or sudden jumps mean the sensor’s on the way out.

When replacing the TPS on a Gran Move, it’s mounted on the side of the throttle body with two small screws and a keyed shaft. Many units are adjustable via slotted holes. Aftermarket and OE procedures call for setting the closed‑throttle position so the idle switch closes at rest (IDL continuity) or the closed‑throttle voltage lands within spec, then tightening the screws. Don’t overtighten — the housing is plastic. Avoid soaking the sensor in cleaner, if the throttle body needs a scrub, remove the TPS first or keep solvents away from it. After fitting, an idle relearn (a few minutes of warm idle with no loads) helps the ECU settle down.

• Common signs of a crook TPS: hesitant take-off, harsh auto shifts, stalling after lift-off, erratic idle, poor fuel economy, and stored TPS fault codes.
• Good practice: check throttle cable free play, clean the throttle bore and plate with intake-safe cleaner, and keep the connector clean and snug.

Popular questions

Where is the TPS on a 1999 Gran Move?
It’s bolted to the throttle body on the intake manifold, opposite the throttle cable quadrant. The connector typically has three or four wires for 5 V reference, signal, earth, and an idle switch.

Do you have to calibrate the TPS after replacement?
Yes, if the replacement has slotted mounting holes. Rotate it slightly to achieve the specified closed‑throttle voltage or idle-switch continuity per the workshop manual, then tighten the screws. A brief idle relearn afterwards is a good idea.

What symptoms point to a failing TPS on this model?
Flat spots on acceleration, hanging or hunting idle, random surging, poor fuel use, harsh or late shifts in the auto, and fault codes related to TPS range or circuit performance are the big giveaways.