Parts for your 2009 Mazda Premacy-Temperature sensors

2009 Mazda Premacy Temperature Sensors

Temperature sensors are definitely used on the 2009 Mazda Premacy. Technical sources such as the Mazda Premacy/Mazda5 (CR) Workshop Manual and Mazda Global Service Support materials detail multiple sensors: an Engine Coolant Temperature (ECT) sensor and Intake Air Temperature (IAT) sensor in the Engine Control System, an Ambient Air Temperature and Evaporator Temperature sensor in the HVAC section, and a Transmission Fluid Temperature sensor for auto models. The factory DTC list (e.g., P0116–P0119 for ECT, P0112–P0113 for IAT) further confirms their presence and role.

On this model, temperature sensors do a heap of behind-the-scenes work to keep the Premacy running sweet. The ECT sensor tells the PCM how hot the engine is so it can sort cold-start enrichment, ignition timing, idle speed, and when to kick the radiator fans on. That same signal also helps protect the engine if things are getting too toasty. The IAT sensor lets the PCM trim fuelling for air density changes, which improves drivability and fuel economy. Inside the cabin, the HVAC uses ambient and evaporator temperature sensors to regulate the A/C, avoid evaporator icing, and keep the set temp steady. Auto transmissions use a fluid temp sensor to refine shift timing and line pressure when cold or under load.

There’s no fixed replacement interval for these sensors, they’re typically “replace on failure.” As part of regular servicing, it’s smart to:

• Scan live data (ECT, IAT, A/C evap temp, ambient) and compare to actual ambient with a thermometer. Odd readings or slow response hint at trouble.
• Inspect connectors and looms near the thermostat housing and intake ducting for heat damage, corrosion, or coolant wicking.
• Maintain the cooling system: correct coolant mix, fresh coolant at the recommended interval, and a healthy thermostat help sensors read accurately.

Common symptoms of a crook temp sensor include hard cold starts, rich running, high fuel use, surging idle, radiator fans stuck on, weak A/C performance, or a check engine light. If replacement’s needed, let the engine cool fully, depressurise the system, catch and reuse/replace coolant as appropriate, and fit a quality O-ring or washer as specified. Avoid over-tightening. For the IAT, ensure the sensor is properly seated in the air box or duct and that there are no intake leaks downstream.

Use genuine or reputable aftermarket parts. After installation, clear codes, check for leaks, and verify stable readings on a scan tool. Done right, these sensors quietly keep the Premacy efficient, reliable, and comfy across Aussie and Kiwi conditions.

Popular questions about 2009 Mazda Premacy temperature sensors

Where is the engine coolant temperature sensor located?
The ECT sensor is typically mounted at the thermostat housing or coolant outlet on the cylinder head, near the upper radiator hose. On many MZR petrol engines used in the Premacy (CR), it sits in the outlet neck. Access is usually from under the bonnet, some covers or hoses may need moving for a clear reach.

Can a faulty temperature sensor cause rough idle or high fuel use?
Yes. If the ECT reads too cold, the PCM enriches the mixture like a permanent cold start, causing rough idle, sootier exhaust, and higher fuel consumption. A misreading IAT can also skew fuelling and timing, making the car feel doughy or hesitant.

Does the Premacy have more than one temperature sensor?
It does. Expect at least the ECT and IAT for engine management, plus ambient and evaporator sensors for the HVAC. Auto models add a transmission fluid temperature sensor. Each one feeds a specific system to manage performance, protection, and comfort.