Parts for your 2021 Mazda Cx-5-Throttle position sensors

2021 Mazda CX-5 throttle position sensors: what they do and when to replace

On the 2021 Mazda CX-5 (Skyactiv-G 2.5/2.5T petrol and Skyactiv-D 2.2), a throttle position sensor is used. Technical Mazda sources — the KF-series Workshop Manual (Engine Control System) and the Electrical Wiring Diagram for this model — describe an electronic throttle body with dual, built-in throttle position sensors (often labelled TPS1/TPS2) and a separate accelerator pedal position sensor. Mazda parts catalogues for the KF CX-5 list the throttle position sensors as integral to the throttle body assembly, not as a standalone service item. That means faults typically require replacement of the complete throttle body and a throttle/idle relearn using a scan tool.

The throttle position sensors on the CX-5’s drive-by-wire throttle body constantly report the throttle plate angle to the powertrain control module. Working alongside the accelerator pedal sensor, they let the computer command smooth torque, idle control and precise fuelling. They’re also critical for cruise control, transmission shift strategy, traction and stability control, and emissions systems. If the readings from the two internal sensors don’t agree, the car will protect itself by limiting power and flagging a fault.

Because the sensors are integrated, servicing focuses on inspection, cleaning and correct replacement of the throttle body when needed. A clean, correctly sealed intake helps the sensors read accurately.

• Common signs of trouble: rough or hunting idle, hesitation on take-off, poor fuel economy, sudden loss of power (limp mode), or the check engine light with codes such as P0121–P0123, P0221–P0223 or P2135.
• Good maintenance habits: keep the air filter fresh, check for cracked intake hoses or vacuum leaks, and avoid hosing electrical connectors. If cleaning the throttle body, use a throttle-safe cleaner, don’t force the butterfly by hand, and let it dry fully before restart.
• Replacement tips: on this model, replace the throttle body as an assembly with a new gasket. Torque fasteners to Mazda spec, reconnect the coolant lines (where fitted), and perform the throttle/idle relearn with a capable scan tool so the PCM can calibrate the new sensors. Clear DTCs and road test. If faults return, check grounds, battery voltage and the pedal sensor before condemning the new part.

Done right, a healthy throttle body and its position sensors keep the CX-5 feeling crisp, predictable and efficient on Aussie and Kiwi roads, whether it’s the weekday commute or a long weekend away.

Popular questions

Does the 2021 Mazda CX-5 have a separate throttle position sensor I can replace?
It doesn’t. On this model, the throttle position sensors are built into the electronic throttle body. If a sensor fails or readings don’t track correctly, the fix is to replace the throttle body assembly. After fitting, a throttle/idle relearn with a scan tool is recommended to restore proper operation.

What are the signs the throttle position sensor is failing on a 2021 CX-5?
Typical clues include a check engine light, erratic idle, hesitation, poor economy, or limp mode. Diagnostic codes like P0121–P0123 or P2135 are common. Before replacing parts, check the throttle body connector, battery health and intake hoses, as these can mimic sensor faults.

Do I need to perform a relearn after replacing the throttle body on a 2021 CX-5?
Yes. Mazda service information calls for an electronic throttle/idle learn procedure after throttle body replacement. Some adaptation can occur with normal driving, but a proper scan-tool relearn is the reliable way to get stable idle and crisp throttle response straight away.