Parts for your 2019 Holden Commodore-Throttle position sensors

2019 Holden Commodore throttle-position-sensor (TPS)

From Holden/GM Service Information (SI) for the ZB Commodore (Opel Insignia B platform) and GM diagnostic sections such as “Engine Controls – Electronic Throttle Control (ETC) Description and Operation” and DTC groups P0121–P0123/P2135, the 2019 Holden Commodore uses an electronic throttle body with integrated, redundant throttle-position sensors. Parts catalogues for GM/ACDelco throttle bodies list the TPS as built-in and non-serviceable. There isn’t a standalone, external TPS on this model, instead, the electronic throttle body houses the sensors, and the accelerator pedal carries a separate accelerator pedal position (APP) sensor.

On this Commodore, the throttle-position-sensor’s job is to tell the engine control module exactly where the throttle plate is, so the ECU can balance air, fuel and spark. Because it’s a drive-by-wire setup, blade angle is commanded by the ECU and verified by two internal TPS tracks for safety. That means smooth take-offs, stable idle and tidy fuel economy when everything’s playing nicely.

There’s no scheduled replacement interval for the TPS because it’s part of the throttle body. During regular servicing, workshops typically check live data for clean, matching TPS signals, scan for codes, and inspect the wiring and connector under the bonnet. A dirty throttle plate can make the sensor readings erratic, so a careful throttle-body clean with the right spray (no soaking, no forcing the blade) is worthwhile at major services, especially on higher‑kilometre cars or those doing lots of short trips.

If faults crop up—think hesitation, limp mode, uneven idle, or the MIL on—common codes include P0121/P0122/P0123 (TPS range/performance) and P2135 (TPS correlation). Because the TPS is integral, replacement means fitting a new throttle body assembly and gasket, checking for intake leaks, and performing a throttle/idle learn. A scan tool (GDS2 or equivalent) makes the relearn quick, some vehicles will relearn after battery reset and a specific idle routine, but a proper scan-tool procedure is best. It’s also smart to verify the accelerator pedal position sensors and grounds before condemning the throttle body.

• Warning signs: erratic idle, poor throttle response, stalling, MIL on, reduced power (limp) mode.
• Service tips: keep the connector dry and secure, clean the throttle plate sensibly, maintain battery voltage during any ECU relearn, and use quality OE-spec parts.

Owners who keep the throttle body clean and the software calibrations current generally enjoy fuss-free throttle behaviour for many years and kilometres.

Popular questions about the 2019 Holden Commodore throttle-position-sensor

Does the 2019 Commodore have a separate TPS I can swap on its own?

No. On this model the TPS is built into the electronic throttle body. If the sensor fails or the signals don’t correlate, the fix is normally to replace the throttle body assembly and then carry out a throttle/idle relearn. The accelerator pedal has its own sensors, so diagnostics should confirm which side is at fault before any parts go in.

What fault codes point to a TPS issue on a ZB Commodore?

Common codes are P0121, P0122, P0123 (throttle position range/performance) and P2135 (TPS 1–2 correlation). P2101/P2119 may appear where the throttle actuator can’t reach the commanded position. A scan of live data should show two TPS signals that track each other smoothly, mismatches, dropouts or noisy traces usually confirm the problem.

Is a relearn needed after cleaning or replacing the throttle body?

Yes. After a throttle body replacement—or even a thorough clean—an idle/throttle relearn helps the ECU set the correct stop positions and airflow targets. A professional scan tool procedure is preferred, though some vehicles will complete an automatic relearn after a battery reset and a short idle routine at operating temperature.