Parts for your 2018 Mazda Cx-5-Throttle position sensors

2018 Mazda CX-5 Throttle Position Sensors (TPS)

Technical sources confirm the 2018 Mazda CX-5 uses throttle position sensors. Mazda’s drive-by-wire Electronic Throttle Control monitors dual TPS signals in the throttle body (often labelled TP1/TP2) alongside the accelerator pedal position sensor. This setup is documented in factory service information and wiring diagrams for the CX-5 (KF).

• Mazda Global Service Support (CX-5 KF Workshop Manual): Engine Control System – Electronic Throttle Control (ETC), and PCM wiring showing TP1/TP2 inputs
• Mazda Electrical Wiring Diagram (CX-5 KF): Throttle Body with integrated position sensors feeding the PCM
• Mazda Electronic Parts Catalogue (CX-5 KF): Throttle body assembly listed as a single unit with non-serviceable built-in TPS

On the 2018 CX-5, the throttle-position-sensors live inside the electronic throttle body and constantly report the throttle plate angle to the engine computer. There are two sensors for redundancy and safety, and the PCM cross-checks them with the accelerator pedal sensor. That live feedback lets the car meter fuel precisely, steady the idle, keep shifts smooth, and manage systems like cruise control, traction and stability. On Skyactiv-D models, a throttle shutter in the intake also uses position sensing to help with EGR and shutdown smoothness.

There’s no set replacement interval for the throttle-position-sensors, they’re designed to last the life of the throttle body. As part of routine servicing, it’s smart to inspect the intake tract and throttle body for contamination. Light carbon or oil film can upset airflow and feel like a TPS fault. If cleaning is needed, use a throttle-body-safe cleaner, keep solvents off electronics, and don’t force the plate by hand. After cleaning or battery disconnect, an idle/throttle learn with a scan tool helps the PCM settle quickly.

Typical warning signs that point to throttle body/TPS issues include a surging or unstable idle, sluggish or jumpy throttle response, an illuminated MIL, cruise control dropping out, or the car going into limp-home mode. Common fault codes include P0121, P0122, P0123, P2135, and related correlation faults. Because the TPS is integrated, replacement usually means fitting a new throttle body assembly. Check the harness and connectors for damage first, poor earths or corroded pins can mimic sensor failures. When replacing, fit a new gasket, torque evenly, clear codes, and perform a throttle/idle relearn with a capable scan tool. There’s no need to “reprogram” the PCM in most cases, but adaptation is important for a smooth idle and crisp response.

Done right, servicing the throttle body and keeping an eye on the throttle-position-sensors helps the 2018 CX-5 run sweet, save fuel, and stay predictable on the open road.

Popular questions about 2018 Mazda CX-5 throttle-position-sensors

Where is the TPS on a 2018 Mazda CX-5?
The throttle-position-sensors are built into the electronic throttle body on the intake manifold. The accelerator pedal has its own position sensor too. On diesel models there’s also an intake shutter with a position sensor that the PCM monitors.

Do I need a relearn after cleaning or replacing the throttle body?
Yes—perform a throttle/idle learn with a scan tool. The PCM will adapt over a few drives, but an explicit relearn speeds up stabilisation, prevents high or low idle, and keeps the shift feel tidy. Clear any fault codes once finished.

Will cleaning fix TPS fault codes?
Cleaning helps if the problem is a sticking plate or airflow issue. If the codes point to electrical faults (like TP1/TP2 correlation), the fix is usually a new throttle body assembly after wiring checks. Always inspect connectors and grounds first.