Ford Flex Ambient Air Temperature Sensor Guide (2009-2019)
Fix incorrect outside temperature readings and A/C problems on your Ford Flex.
- A faulty ambient air temperature sensor is a common, minor issue that primarily affects your A/C and dash temperature display.
- Replacement is a very easy DIY job that takes less than 15 minutes, requiring no special tools.
- Motorcraft is the OEM part, but reputable aftermarket brands like Dorman and Standard Ignition offer a reliable and more affordable alternative.
- Before assuming a major A/C problem, check for an incorrect outside temperature reading, as this simple sensor is often the culprit.
Common Symptoms of a Bad Sensor
When the ambient air temperature sensor fails on a Ford Flex, you'll likely notice one or more of these issues. Because of its location, it can be damaged in a minor front-end collision.
- Incorrect Temperature on Dash: The most obvious sign is an incorrect temperature reading on your dashboard or infotainment screen. It might be stuck at a certain temperature, read extremely high or low (like -40°F), or just show dashes.
- A/C Not Blowing Cold: The automatic climate control system relies on the sensor's reading. If the sensor tells the computer it's cold outside, the A/C compressor may not turn on, even on a hot day. 🎬 See how a faulty sensor causes climate control issues.
- Automatic Climate Control Acts Up: If you use the "Auto" setting, it may not be able to maintain a steady temperature inside the cabin because it's getting bad information about the outside conditions.
- Check Engine Light: In some cases, a completely failed sensor can trigger a Check Engine Light with codes like P0071, P0072, or P0073.
Choosing the Right Aftermarket Sensor
You don't have to buy the most expensive sensor to get your system working again. Here’s a breakdown of your options.
Brand Quality Tiers
| Tier | Brands | Honest Assessment |
|---|---|---|
| OEM | Motorcraft | Motorcraft is Ford's official brand. It guarantees perfect fit and function, identical to the part your Flex was built with. If you want zero guesswork, this is the choice. It costs more, but for a critical sensor, it's a safe bet. |
| Premium Aftermarket | Dorman, Standard Ignition (SMP) | These brands are well-known in the aftermarket and are trusted by many mechanics. They design their parts to meet or exceed OEM standards and are a reliable, cost-effective alternative to Motorcraft. Dorman's OE Solutions line specifically aims to provide a direct-fit replacement. |
| Standard Aftermarket | Holstein, URO Parts, Skyward, True Tech | These brands offer a budget-friendly option. They are designed to function as a direct replacement and often come with good warranties. For a simple sensor like this, a standard aftermarket part is often sufficient and provides great value. |
Pro Tip: Replacement is extremely easy for this part. It's a great DIY job for any skill level. The sensor is typically located in front of the radiator, clipped into the radiator support. You simply unplug the old one, unclip it, and clip the new one in its place.
🎬 Watch: A quick walkthrough on testing and replacing the sensor.Frequently Asked Questions (FAQ)
Where is the ambient air temperature sensor on my Ford Flex?
On the 2009-2019 Ford Flex, the sensor is almost always located at the front of the vehicle, clipped into the radiator core support, behind the front grille. You should be able to see it by looking through the grille. Its location ensures it gets a good reading of the outside air while the car is moving.
Can a bad sensor really stop my A/C from working?
Yes. The automatic climate control system uses the outside temperature reading to decide whether to engage the A/C compressor. If the sensor is faulty and reports a very cold temperature (e.g., 30°F) on a hot day (e.g., 90°F), the system will prevent the A/C from running to avoid potential damage, leaving you with no cold air.
Will a bad ambient temp sensor cause a Check Engine Light?
It can. If the sensor's circuit is open, shorted, or provides a reading that is completely out of range, the Powertrain Control Module (PCM) can log a fault and turn on the Check Engine Light. Common codes include P0071 (Range/Performance), P0072 (Low Input), and P0073 (High Input).
🎬 Watch: How to diagnose and fix a P0073 circuit code.Do I need to reset the computer after replacing the sensor?
Generally, no special reset is required. After replacing the sensor, the system should start reading the correct temperature after a few minutes of driving. In some rare cases, a Ford-specific TSB mentions resetting learned values, but for a simple swap, it's usually plug-and-play. If a Check Engine Light was on, you may need to clear the code with a scan tool or by disconnecting the battery for about 15 minutes.
Helpful Videos
Technical Specifications
OEM Part Numbers: AE5Z12A647A DY1137
2-pin connector, clip-on mounting style. Typically located in the front grille/radiator support area.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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