Parts for your 2007 Mazda Cx-9-Throttle position sensors

2007 Mazda CX‑9 Throttle Position Sensors (TPS): What’s Fitted and How They’re Serviced

Technical sources confirm the 2007 Mazda CX‑9 does use throttle position sensors. The Mazda Workshop Manual for the CX‑9 (Engine Control System – Electronic Throttle Control) details a throttle body with an internal DC motor and dual throttle position sensors (TPS1/TPS2) for redundancy. Factory wiring diagrams show two throttle position signal circuits from the throttle body to the PCM, and the diagnostic section lists TPS‑related DTCs (including P0121–P0123, P0221–P0223, P2135). Mazda’s parts catalogue also supplies the throttle body as a complete assembly with the TPS integrated and not serviced separately.

On the 2007 Mazda CX‑9, the throttle position sensors live inside the electronic throttle body, working alongside the motor that opens the butterfly. Their job is to tell the engine computer exactly how far the throttle blade is open, so fuel and spark can be dialled in smoothly. The system is drive‑by‑wire, so there’s also an accelerator pedal position sensor at the pedal, the PCM constantly cross‑checks the pedal inputs with the two TPS signals for safety and accuracy.

This setup isn’t a routine “replace at X kilometres” item, but it is critical. If the TPS readings drift or drop out, the CX‑9 can stumble, idle rough, surge, or throw the car into limp mode with warning lights on. Common fault codes to see when the TPS goes off spec include P0121, P0122, P0123, P0221, P0222, P0223 and P2135.

Good servicing habits help. Keep the air filter fresh and the intake sealed so dust doesn’t gum up the throttle blade. When cleaning the throttle body, use a proper throttle body cleaner and a lint‑free cloth, don’t soak the unit or pry the blade by hand, and avoid flooding the electronics side. It’s also smart to inspect the throttle body connector for corrosion or broken pins, and check the harness for rubbing near the intake.

If replacement is needed, the TPS is part of the throttle body on this model, so the whole assembly is swapped. After fitting, a throttle/idle relearn is required. A scan tool procedure is best, but many technicians can complete a manual relearn by warming the engine and letting it idle without loads for several minutes. Clear any stored codes, confirm stable idle and throttle response, and road‑test to verify the fix. With quality parts and correct relearn, the CX‑9’s throttle control returns to smooth, reliable operation for plenty more kilometres under the bonnet.

• Symptoms to watch: erratic idle, hesitation, reduced power, cruise control dropping out, MIL on.
• Service tip: stable battery voltage is important, low voltage can trigger throttle and TPS faults.

Does the 2007 Mazda CX‑9 have a separate TPS I can replace?

No. On this model the TPS is integrated into the electronic throttle body with a pair of sensors. If the TPS is faulty, the usual repair is to replace the entire throttle body assembly. That’s how Mazda supplies the part and how the workshop manual directs the repair.

What are the classic signs of a failing TPS on a 2007 CX‑9?

Drivers often report rough or high idle, hesitation off the line, sudden loss of power, or the car dropping into limp mode. The check engine light comes on and scan tools commonly show codes like P0121–P0123 or P2135. If those symptoms line up, start with wiring/connector checks and throttle body inspection.

Is a throttle relearn needed after battery disconnect or throttle body replacement?

Yes. After replacing the throttle body—or even after a long battery disconnect—the PCM may need to relearn the throttle and idle positions. Many scan tools have a guided “ETC Relearn.” If one isn’t available, a manual idle learn (engine at operating temp, no loads, let it idle several minutes) usually does the trick, followed by a short road test.