Parts for your 1998 Daihatsu Terios-Throttle position sensors

1998 Daihatsu Terios Throttle Position Sensor (TPS) — What it does and how to look after it

Yes, the 1998 Daihatsu Terios uses a throttle position sensor. Technical references including the Daihatsu Terios J100 Series Workshop Manual (Engine Control—EFI), Autodata model coverage for 1998, and Daihatsu OBD-II documentation listing P0120–P0124 for the J100 confirm a TPS is fitted to the 1.3‑litre EFI engine. It’s a drive‑by‑cable setup, and the TPS is mounted on the throttle body to tell the ECU exactly how far the throttle is opened.

The TPS is the ECU’s eyes on driver demand. As the throttle plate moves, the TPS sends a changing voltage, helping the ECU manage fuelling, ignition timing, idle control and automatic transmission shift strategy (where applicable). Smooth, accurate TPS feedback equals tidy throttle response, good fuel economy and clean emissions—handy whether it’s a city runabout or a wee off‑road trekker.

As part of routine servicing, it’s smart to check the TPS and the throttle body. The connector can cop moisture and dust under the bonnet, and the throttle shaft can build up carbon that affects closed‑throttle accuracy. With a scan tool, look for a stable “Throttle Position” at idle (typically around 0–1%) and a smooth sweep to 100% with no dropouts. If testing with a multimeter per the workshop spec, you’re generally looking for roughly 0.5–0.7 V at closed throttle rising smoothly to about 4.0–4.5 V at wide open.

• Common clues the TPS is on the way out: hesitant take‑off, flat spots, erratic idle, higher fuel use, and an engine light with codes like P0120–P0124.
• Maintenance tips: clean the throttle body bore and plate, inspect the TPS harness for loose pins, and ensure the throttle cable has a hint of free play.
• Replacement advice: disconnect the battery, unplug the 3‑pin TPS, remove the two screws, swap the unit, and lightly torque the new screws (about 3–4 N·m). If the TPS has slotted holes, rotate it slightly to set the closed‑throttle value per the manual, then perform an idle relearn (warm up, let it idle a few minutes, then a short drive cycle).

Most owners will be fine with inspection and cleaning during a standard service every 20,000 km. If voltage is jumpy or out of spec, fit a quality replacement—cheap units can behave badly once hot. A quick scan‑tool check afterwards keeps everyone happy.

Popular questions about 1998 Daihatsu Terios throttle position sensors

Where is the TPS on a 1998 Terios?
It’s bolted to the side of the throttle body, opposite the throttle cable linkage, and uses a 3‑pin connector. Lift the air intake duct off the throttle body and it’s right there, easy to spot and reach with a small screwdriver.

Can the TPS be adjusted or does it just plug and play?
Many Terios TPS units are slightly adjustable via slotted mounting holes. After fitting, rotate it a touch to set the closed‑throttle signal to spec, then nip the screws. If your replacement is a fixed‑position type, it’s plug‑and‑play—just confirm idle and sweep values with a scan tool.

What fault codes point to a dodgy TPS on this model?
Expect OBD‑II codes like P0120 (TPS circuit), P0121 (range/performance), P0122 (low), P0123 (high) and P0124 (intermittent). These often pair with symptoms like stumbles on acceleration or a hunting idle. Always check wiring and the throttle body before condemning the sensor.