BMW 335i (2007-2015) Ambient Air Temperature Sensor Replacement Guide
Is your BMW 335i displaying the wrong outside temperature or having A/C problems? This guide explains what you need to know.
- Failure is almost always caused by physical damage to the sensor or its wiring due to its vulnerable location in the front bumper.
- Aftermarket sensors from brands like Dorman, Standard Ignition, and URO Parts are reliable and cost-effective alternatives to the expensive OEM part.
- Before buying a new sensor, visually inspect the area to ensure the old sensor and its wiring are not simply disconnected or damaged.
- Replacement is a simple, plug-and-play DIY job once you gain access, which may require removing an underbody shield.
Is Your 335i Lying About the Weather?
The most common reason for a BMW 335i owner to replace the ambient air temperature sensor is a strange reading on the dashboard. Because the sensor is located in the front bumper area, it is highly vulnerable to damage from road debris, parking curbs, snowbanks, and minor front-end impacts. Often, the problem isn't that the sensor has failed on its own, but that it, or its wiring, has been physically damaged or torn away.
Symptoms of a Bad Ambient Air Temperature Sensor
When this sensor fails or gets disconnected, your BMW will let you know with some obvious signs:
- Incorrect Temperature Display: The dashboard will show a fixed, illogical temperature, most commonly -40°F or 122°F.
- Automatic Climate Control Problems: The 'Auto' function for your A/C and heat will not work correctly. The system may blow hot air on a warm day or cold air when you need heat because it's getting bad information about the outside temperature.
- Service Engine Soon Light: A fault in the sensor circuit can trigger a warning light on your dash and store error codes like P0070, P0071, P0072, or P0073.
- Radiator Fan Running Constantly: In some cases, a false high-temperature reading can trick the car into running the radiator fan at full speed, even when the engine is cool.
Pro Tip: Check for Damage First
Before ordering a new part, look behind the front bumper's lower grilles (you may need a flashlight). See if the sensor is missing entirely or if the wires are cut or frayed. Sometimes, after a fender bender, a body shop may forget to reconnect it. This can save you from buying a part you don't need.
Choosing the Right Aftermarket Sensor
For a simple sensor like this, an aftermarket replacement is a perfectly reliable and cost-effective choice. The technology is not complex, and quality aftermarket brands offer excellent value compared to the much higher-priced OEM part. Here is a breakdown of the available brand tiers:
- Value Tier (Dorman): Dorman is a well-known aftermarket brand offering a direct-fit replacement that functions like the original. It's a budget-friendly solution for this common problem.
- Standard Tier (Standard Ignition): Standard Motor Products (SMP) is a reputable manufacturer known for producing quality components that meet or exceed original specifications. They are a solid choice for reliability.
- Specialty Tier (URO Parts): URO Parts specializes in parts for European vehicles like your BMW. They offer a direct replacement designed to withstand harsh conditions and often come with a good warranty.
Cost of Replacing a 2007-2015 BMW 335i Ambient Air Temperature Sensor
| Part Type | Price Range |
|---|---|
| New Aftermarket Sensor | $19.87 - $57.94 |
| New OEM Sensor | $55 - $75 |
| Shop Labor (simple replacement) | $50 - $100 |
Installation Overview
Replacing the sensor is a simple plug-and-play job. The main challenge is access. The sensor is a small, probe-like component that pushes into a holder in the front bumper area.
- On E90, E92, E93 models (2007-2013), the sensor is typically located in the lower bumper grille area, on either the driver's or passenger's side. Some owners can reach it by removing the plastic undertray, while others find it necessary to remove the front bumper for full access.
- On F30 models (2012-2015), the sensor is also in the lower front area and is typically accessed from underneath the car by removing the engine splash shield.
Once you can reach it, you simply unplug the old sensor and plug in the new one. If the wiring is damaged, you will need a new connector pigtail to splice into the harness.
Common Ordering Mistake
Do not confuse the Ambient Air Temperature Sensor with the Cabin Air Temperature Sensor or the Engine Intake Air Temperature (IAT) Sensor. They are different parts with different functions. Verify you are ordering the sensor for the outside temperature, which is located at the front of the vehicle.
Frequently Asked Questions
Why does my dash say -40°F?
This is the default reading the BMW computer shows when it detects an open circuit from the sensor, meaning the sensor is unplugged, missing, or the wires are completely cut. A reading of 122°F often indicates a short circuit.
Can I replace this sensor myself?
Yes, this is a very DIY-friendly repair if you are comfortable with basic tools and potentially removing the plastic splash shield from under your car. The part itself just plugs in.
What if a new sensor doesn't fix the problem?
If you plug in a new sensor and the reading doesn't change, the problem is almost certainly in the wiring or the connector. Inspect the wires leading to the sensor for breaks, corrosion, or damage from a previous impact. You may need to repair the wiring or replace the connector pigtail.
Are there any recalls for this part?
No, there are no specific recalls or technical service bulletins (TSBs) from BMW or the NHTSA for the ambient air temperature sensor on the 2007-2015 335i. Failure is almost always due to external physical damage.
Technical Specifications
OEM Part Numbers: 65816936953 65816905133 65810141199 65812962955 65812979071
2-pin male blade terminal connector. Mounts in the front bumper 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.
- BMW 335i:
- 🛍️ Shop This Part
- Is Your 335i Lying About the Weather?
- Symptoms of a Bad Ambient Air Temperature Sensor
- Pro Tip: Check for Damage First
- Choosing the Right Aftermarket Sensor
- Cost of Replacing a 2007-2015 BMW 335i Ambient Air Temperature Sensor
- Installation Overview
- Common Ordering Mistake
- Frequently Asked Questions
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