Fixing the Buzz: A Guide to the 2013-2015 Acura RDX Active Noise Cancellation Module

What the Active Noise Cancellation Module Does on Your RDX

Think of the Active Noise Cancellation (ANC) system in your 2013-2015 RDX like a pair of noise-canceling headphones for your entire car. Its only job is to reduce persistent, low-frequency noises that can be tiring on long drives. The system uses microphones to constantly monitor engine and road noise, and then it generates an opposite sound—a sort of 'anti-noise'—that it plays through the car's audio system. When the original noise and the 'anti-noise' meet, they effectively cancel each other out, making the cabin significantly quieter. This system is always active when the car is running, regardless of whether your radio is on or off.

Common Symptoms of a Failing ANC Module

When the ANC module begins to fail, it can create more noise than it cancels. The symptoms are almost always audio-related and can be very annoying.

• Buzzing or Humming from Speakers: The most common symptom is a constant, low-frequency buzz or hum that comes from the speakers. This noise is present even when the audio system is turned off and may change pitch with engine RPM.
• Popping or Crackling Sounds: Intermittent popping or static-like crackles can also be heard from the speakers.
• Phantom Bass Notes: Some owners report hearing random, deep bass notes or a 'thump' sound, especially after installing an aftermarket subwoofer. This happens because the ANC module's signals interfere with the new audio equipment.

No specific OBD-II trouble codes are associated with a failing ANC module, as it does not typically communicate with the main engine control unit in a way that would trigger a check engine light.

Diagnosing the Problem: Is It Really the ANC Module?

Before buying a replacement part, it's easy to confirm if the ANC module is the source of the unwanted noise. Since the module is the cause, unplugging it should make the noise stop immediately.

1. Locate the Module: The ANC module is a small metal box located behind the glove box on the passenger side.
2. Access the Module: You will need to open the glove box, empty it, and press in on the sides to release the stops. This allows the glove box to swing down completely, giving you access to the area behind it.
3. Unplug the Connector: Find the ANC module (it will have part number 39200-TX4-A11 or similar printed on it) and disconnect the single electrical connector.
4. Test Drive: Start the car. If the buzzing, humming, or popping noise is gone, you have successfully identified the ANC module as the problem.

Known Issues, TSBs, and Recalls

There are no official recalls or Technical Service Bulletins (TSBs) from Acura specifically for a failing Active Noise Cancellation module on the 2013-2015 RDX. However, the issue of buzzing and humming caused by the module is a widely documented complaint among owners in online forums and communities. While newer Acura models have TSBs for similar popping sounds, those are related to different network connector issues and do not apply to this generation of RDX.

Buying a Used 2013-2015 RDX ANC Module

Since this is a non-wear item, a used OEM module from a reputable recycler is an excellent, cost-effective alternative to an expensive new part. Here’s what to look for:

• Match the Part Number: The most critical step is to match the part number. The primary number is 39200-TX4-A11. You may also see longer variations like 39200-TX4-A114. As long as the base number `39200-TX4-A11` matches, it should be compatible.
• Inspect the Connector: Ask for photos of the connector pins. Ensure they are straight, clean, and free of any green or white corrosion, which would indicate water damage.
• Why Used OEM is a Good Choice: Aftermarket versions of this specific module are not manufactured. A used OEM part is identical to what the dealer sells, often at a fraction of the price. Since failure is electronic rather than mechanical, a part from a lower-mileage vehicle is theoretically better, but condition is more important than age or mileage.

Programming and Installation

The Active Noise Cancellation module is a self-contained audio processor. It does not require programming, flashing, or a dealer visit after installation. It is a plug-and-play part. While some generic part listings may mention programming is required, specialists who rebuild these units confirm it is not necessary. The module is not tied to the vehicle's immobilizer or VIN.

Cost to Replace the Active Noise Cancellation Module

Step-by-Step Replacement Guide

Replacing the ANC module is a straightforward job that most DIY mechanics can complete in under 30 minutes.

1. Disconnect the Battery: As a safety precaution, disconnect the negative terminal of the battery.
2. Access the Glove Box: Open the passenger-side glove box and empty its contents.
3. Lower the Glove Box: Press inward on the flexible sides of the glove box to release the rubber stoppers. This will allow the entire assembly to swing down and hang from its hinges, revealing the area behind it.
4. Locate and Unbolt the Old Module: The ANC module is a small, silver metal box mounted in this area. It is typically held in place by one or two 10mm bolts. Remove the bolts.
5. Disconnect the Electrical Connector: With the module unbolted, press the release tab on the electrical harness and pull it straight out.
6. Install the New Module: Connect the electrical harness to the new module, bolt it into place, and then re-secure the glove box by lifting it and pushing it back until the stoppers click into place.
7. Reconnect the Battery: Reconnect the negative battery terminal. The job is now complete.

Frequently Asked Questions (FAQ)