Parts for your 2006 Toyota Bb-Throttle position sensors

2006 Toyota bB throttle-position-sensor: purpose, servicing and replacement

Based on Toyota service literature for the QNC20–QNC25 bB range and the Toyota Electronic Parts Catalogue for these models, the 2006 Toyota bB is fitted with a throttle-position-sensor (TPS). On the K3-VE and 3SZ-VE petrol engines used in this generation, the TPS is part of the throttle body assembly (some variants have an electronic throttle body with dual TPS tracks). Toyota diagnostic documents also list TPS-related OBD-II fault codes (such as P0120–P0124) for this platform, confirming the sensor’s role.

On a 2006 bB, the TPS tells the engine control module exactly how far the throttle plate is open. That signal is crucial for fuelling, ignition timing, idle control and, on autos, shift behaviour. With electronic throttle versions, there are two TPS circuits for redundancy, keeping things safe if one track drifts. Day to day, a healthy TPS helps the bB feel smooth off the line, keeps the idle tidy under the bonnet, and trims petrol use on the open road.

Common hints that the TPS is on the way out include a fluttery or high idle, flat spots on take-off, sudden surges, harsh gear changes, and the check engine light. A scan tool reading live data will show the VTA/VTA2 signals stepping cleanly from closed to wide open, if they jump about or don’t agree, there’s a problem. Note that on many bB units the TPS is integrated with the throttle body, so replacement may mean swapping the whole assembly rather than just the sensor.

As part of regular servicing, it’s worth: gently cleaning the throttle bore and plate with a throttle-safe cleaner (don’t drown the sensor), checking the connector for corrosion or a loose fit, and inspecting the harness for chafe near the throttle body. After replacing a throttle body or TPS, carry out an idle/throttle learn. With Toyota diagnostic gear this is a guided routine, without it, a battery-off reset followed by a proper warm-up and idle period often does the trick. Use a fresh throttle body gasket, torque the fasteners evenly, and avoid levering on the plastic housing. Quality OE or reputable OEM parts are the go—cheap copies can cause voltage drift and repeat faults, costing more in labour and fuel over the kilometres.

• Typical symptoms: erratic idle, hesitation, poor fuel economy, limp mode, DTCs P0120–P0124/P2135.
• Service tips: clean throttle carefully, check plugs and earths, verify smooth voltage sweep via scan data.
• After replacement: perform throttle/idle relearn and clear codes, road test over mixed conditions.

Popular questions

Does the 2006 Toyota bB actually have a TPS?
Yes. Technical references for the QNC20–QNC25 bB show a throttle position circuit and a throttle body assembly that incorporates the sensor (and, on electronic throttle versions, dual sensor tracks). It’s a key input the ECU relies on for fuelling and driveability.

How is a TPS/throttle body relearn done on a 2006 bB?
With Toyota-compatible diagnostics, run the throttle/idle learn after fitting. Without a scan tool, disconnect the battery for a few minutes, start the engine without touching the pedal, let it idle until the radiator fan cycles, then drive with light-to-moderate throttle so the ECU can map the new position. Clear any fault codes and recheck live data.

Can the TPS be replaced separately on a 2006 bB?
It depends on the exact engine/throttle body fitted. Many units have the TPS integrated, meaning you replace the complete throttle body. If yours has a detachable sensor, it can be swapped, but set-up is critical—ensure the closed-throttle voltage is within spec and verify a smooth sweep via a scan tool.