BMW 750Li Ambient Air Temperature Sensor Guide (2006-2015)
Is your BMW 750Li's A/C acting up or showing the wrong outside temperature? Your ambient air temperature sensor is the likely culprit.
- A faulty ambient air temp sensor is a common, inexpensive fix for A/C issues and incorrect temperature displays.
- The sensor is located in a vulnerable spot on the front driver's side, so check for physical damage or a missing sensor first.
- This is an easy DIY replacement that most owners can do in under 30 minutes with basic tools.
- Aftermarket brands like Dorman, Standard Ignition, and URO are cost-effective alternatives for this simple part.
Is Your 750Li's A/C Acting Strange? Check This Sensor First.
If your 2006-2015 BMW 750Li starts showing a wildly incorrect outside temperature, or if the automatic climate control isn't working as it should, a faulty ambient air temperature sensor is a common cause. This small, inexpensive part plays a surprisingly important role in your car's comfort systems. Because of its location, it's also vulnerable to damage from road debris, curbs, and weather.
Symptoms of a Failing Ambient Air Temperature Sensor
- Incorrect Temperature Display: The most obvious sign is the temperature on your dashboard or iDrive screen being completely wrong, sometimes showing extreme values like -40°F or 122°F.
- A/C and Heater Problems: The automatic climate control may stop working correctly. The system relies on the sensor's reading to decide how to adjust cabin temperature, so a bad reading can cause it to blow warm air when you want cold, or vice-versa.
- Check Engine Light: A faulty sensor can trigger a Check Engine Light and store diagnostic trouble codes (DTCs) in the car's computer. Common codes include P0070, P0071, P0072, and P0073. 🎬 Learn more about diagnosing P0071 codes and sensor symptoms.
Known Issues & Location
The ambient air temperature sensor on many BMWs, including the 7 Series, is located in the lower front bumper area, often in the driver's side wheel well or behind the grille. This exposed position makes it susceptible to being damaged or knocked off by road debris, ice, or parking curbs. Sometimes the sensor itself is fine, but the wiring gets damaged, leading to the same symptoms.
Choosing the Right Aftermarket Sensor
For a simple sensor like this, an aftermarket part is a perfectly reasonable and cost-effective choice compared to a Genuine BMW part. The key is to choose a brand with a decent reputation. Based on your vehicle, here are the available options:
| Brand | Our Assessment | Price Tier |
|---|---|---|
| Standard Ignition (SMP) | A well-regarded aftermarket brand known for producing reliable electronic components. Often considered a solid alternative to OEM without the high price tag. | $$ |
| Dorman | Dorman offers a wide range of parts and is known for creating solutions to common OEM problems. Quality can sometimes be inconsistent depending on the part, but for a simple sensor, they are generally a reliable, budget-friendly option. | $ |
| URO Parts | URO Parts specializes in European vehicles and offers very competitive pricing. However, their quality can be a topic of debate in BMW forums, with some owners preferring to avoid them for critical components. For a non-critical sensor like this, many find it to be an acceptable budget choice. | $ |
Pro Tip: Check the Connector!
Before ordering a new sensor, inspect the old one and its electrical connector. It's common for the connector or wiring to be damaged rather than the sensor itself. If the connector is corroded or broken, you may need a new pigtail connector as well.
Frequently Asked Questions (FAQ)
Where is the ambient air temperature sensor located on my 2006-2015 750Li?
The sensor is typically located in the front lower bumper area, often on the driver's side, mounted in the fender liner or near the brake cooling duct. 🎬 Watch this video to see the sensor location on various BMW models. You may need to turn the wheel and remove a few screws from the plastic wheel well liner to access it.
Can I replace this sensor myself?
Yes, this is a very DIY-friendly job. It usually involves removing a few plastic fasteners, unplugging the old sensor, and plugging in the new one. No special tools are required, and it can typically be done in under 30 minutes.
🎬 See a step-by-step walkthrough of the sensor replacement process.Will a bad ambient temp sensor cause a Check Engine Light?
Yes, it can. If the sensor's circuit has a problem (like being open or shorted), the engine control module (ECU) will detect it and store a fault code, which illuminates the Check Engine Light. Common codes are in the P0070-P0074 range.
Why does my car show -40 degrees?
When the sensor is missing, disconnected, or the circuit is open, many BMW systems default to a reading of -40°F or -40°C. This is a clear sign that the computer is not receiving a valid signal from the sensor.
Helpful Videos
Technical Specifications
OEM Part Numbers: 65816905133
A two-pin negative temperature coefficient (NTC) sensor that provides outside air temperature data to the vehicle's computer systems.
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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.
- BMW 750Li: