Parts for your 2009 Mazda Premacy-Throttle position sensors

2009 Mazda Premacy throttle position sensor: what it does and how to look after it

On the 2009 Mazda Premacy (also known as Mazda5, CR series), a throttle position sensor (TPS) is definitely used. Technical references such as the Mazda Premacy/Mazda5 (CR, 2008–2010) Workshop Manual and the Mazda Electronic Parts Catalogue list the TPS as being integrated into the electronic throttle body, alongside the throttle actuator motor, with dual TP sensor tracks for redundancy. The manual also notes the TPS is not serviced separately from the throttle body on the LF/L3 petrol engines, replacement is by throttle body assembly. Diesel variants use a throttle plate for EGR/shut-off that likewise includes a position sensor.

On this model, the TPS tells the powertrain control module exactly where the throttle plate sits so it can manage fuelling, ignition timing, idle speed control and even auto-trans shift behaviour. Because the Premacy uses drive-by-wire, the TPS is part of the safety net that cross-checks with the accelerator pedal position sensors. That twin-track design helps the PCM spot any mismatch and keep things tidy under the bonnet.

When it comes to servicing, the TPS itself isn’t a separate bolt-on bit. If the sensor goes out of range or fails, the cure is a throttle body assembly. Typical hints it’s on the way out include erratic idle, a stubborn throttle response, cruise control dropping out, poor fuel economy, or fault codes like P0121–P0123 and limp-home behaviour. Before replacing parts, always inspect the throttle body connector and harness for corrosion or broken pins, as a dodgy plug can mimic a bad TPS.

Good maintenance goes a long way. Keep the throttle bore clean with the right cleaner, but don’t force the butterfly or flood the housing. Avoid poking solvent into the sensor area. If the throttle body is replaced or removed, use a new gasket and follow the workshop torque specs. A throttle/idle relearn is usually required—ideally with a scan tool—to get the idle and tip-in feeling right. After any work, check for pending codes and take it for a gentle drive so the PCM can settle. If the car’s done a fair few kilometres, it’s also smart to check the accelerator pedal position sensor values at the same time, as both signals are used together to keep the Premacy smooth and safe.

• Common symptoms: uneven idle, hesitation, harsh shifts, higher fuel use, MIL on with P0121–P0123.
• Service tips: inspect wiring, clean throttle bore carefully, replace throttle body if TPS fault persists, perform relearn.

FAQs

Does the 2009 Mazda Premacy have a separate TPS or is it part of the throttle body?
It’s built into the electronic throttle body and isn’t sold as a stand-alone sensor on the LF/L3 petrol engines. If the TPS fails, the fix is to replace the throttle body assembly. Diesel variants use a similar integrated position sensor on the throttle plate unit.

Can a faulty TPS be cleaned or does it have to be replaced?
If the TPS element itself is faulty, cleaning won’t revive it. Cleaning helps if the throttle plate is sticking, but sensor faults require a throttle body assembly. Always rule out wiring or connector issues first.

Do I need to do a relearn after replacing the throttle body on a 2009 Premacy?
Yes. A throttle/idle relearn (preferably with a scan tool) helps the PCM recalibrate the new unit, restoring a stable idle and proper throttle response. Skipping this can leave the idle high, low or a bit wonky.