Parts for your 2011 Mazda Premacy-Temperature sensors

2011 Mazda Premacy temperature-sensors

Based on Mazda’s factory Workshop Manual for the 2010–2013 Mazda5/Premacy (CW), the Mazda Electronic Service Information System wiring diagrams, and standard OBD‑II documentation listing DTCs such as P0117/P0118 (Engine Coolant Temperature), P0113 (Intake Air Temperature) and P0128 (Coolant Thermostat/Temperature), temperature-sensors are absolutely fitted to the 2011 Mazda Premacy. The manual details the Engine Coolant Temperature (ECT) sensor feeding the PCM, an Intake Air Temperature (IAT) sensor (separate or integrated with the MAF depending on engine), an ambient air sensor for HVAC and display, A/C refrigerant temperature/pressure sensing, and—on applicable variants—automatic transmission fluid temperature and diesel exhaust gas temperature (DPF) sensors.

On the 2011 Premacy, temperature-sensors quietly keep everything running sweet. The ECT sensor tells the PCM how warm the engine is so it can trim fuel and ignition, manage idle, and kick the radiator fans on and off. The IAT sensor helps fine‑tune the air–fuel mix, while the ambient sensor keeps the climate control honest and the dash reading accurate. Diesel models may also use exhaust gas temperature sensors to protect the DPF and optimise regens. If the vehicle has an auto, a fluid temperature sensor helps protect the transmission under load or on hot days.

They’re not usually a scheduled service item, but giving them a bit of attention during servicing saves hassles later. A quick scan-tool check of live data (ECT cold vs ambient, warm-up rate, IAT plausibility) is an easy pick-up for drifting readings. Inspect connectors for corrosion and broken locks, and make sure harnesses near the radiator and front bumper aren’t chafed.

If replacing the ECT sensor, start with a cool engine, catch and top up coolant, fit a new O‑ring or sealing washer, and torque to spec from the workshop manual. Refill with the correct Mazda FL22 coolant mix and bleed air, watch for the thermostat opening and stable fan cycling. For IAT integrated in the MAF, avoid touching the element—use MAF‑safe cleaner only. Ambient sensors live in the front bumper area, they can be knocked in minor bumps, so check mounting and reading plausibility.

Common clues that a temp sensor’s on the fritz include hard cold starts, the radiator fans roaring all the time, poor fuel economy, a lazy temp gauge, weak A/C performance, or codes like P0117/P0118/P0128. Use quality OEM or equivalent parts, clear codes, and perform any idle/PCM relearns noted in the Mazda manual.

• Tip: Compare ECT on a cold start to the outside temp, a big mismatch points to a dodgy sensor or wiring.

Popular questions

Where is the engine coolant temperature sensor on a 2011 Premacy?
The ECT sensor is threaded into the engine’s coolant passage, typically near the thermostat housing or cylinder head outlet. On the CW Premacy, it’s accessible from the top with some intake plumbing moved aside. Always check the workshop diagram for your specific engine code.

Does the 2011 Premacy diesel have exhaust temperature sensors?
Yes, diesel variants use exhaust gas temperature sensors before and/or after the DPF. They monitor heat to protect the DPF and control regeneration. Faults here can trigger limp mode or DPF warnings.

Do I need to bleed the cooling system after replacing the ECT sensor?
Yes. Any time the cooling circuit is opened, refill with the correct coolant and bleed air per the Mazda procedure. Watch heater output and fan cycling, and recheck the coolant level after a short drive.