2019-2024 Buick Enclave ANC Module: Fixing Audio Loss, Buzzing, and Water Damage

Known Issues: Water Damage from HVAC Condensation (TSB 20-NA-025)

The most widespread issue affecting the Active Noise Cancellation (ANC) module in 2019-2024 Buick Enclaves is water intrusion. General Motors issued Technical Service Bulletin (TSB) 20-NA-025 for 2018-2019 models, but the design flaw may affect later years as well. The bulletin states that condensation from the vehicle's HVAC (air conditioning) system can drip directly onto the ANC module through its ventilation slots.

This water damage can short-circuit the module, leading to a variety of audio system problems. The official GM fix involves replacing the failed module and, crucially, installing a newly designed plastic shield (GM Part No. 84667409) that covers the top of the new module to deflect any future condensation. Any replacement, whether with a new or used part, should include the installation of this shield to prevent the problem from recurring.

Symptoms of a Failing Active Noise Cancellation Module

When the ANC module fails, it can cause a range of symptoms beyond just an increase in cabin noise. Because it is integrated with the audio system, its failure often presents as a major stereo problem. Common symptoms include:

• Complete Loss of Audio: The most common symptom is the total silence from the car's speakers. This affects the radio, Bluetooth audio, and any other media source.
• No Chimes or Warning Sounds: The failure often silences all system sounds, including the turn signal 'click-clack,' seatbelt reminders, and backup sensor alerts.
• Abnormal Speaker Noises: You may hear loud and unpleasant sounds like popping, buzzing, static, or a deep booming/moaning noise. These sounds can occur even when the radio is turned off.
• Interference with Aftermarket Subwoofers: If you've installed an aftermarket subwoofer, a faulty ANC system may interpret the bass as noise and try to cancel it, resulting in a weird thumping or humming sound.

Buying a Used Active Noise Cancellation Module

A used OEM module is an excellent, cost-effective solution for this repair, especially since the failure is typically caused by an external factor (water) rather than internal component wear. When purchasing a used module, follow these guidelines:

• Verify the Part Number: Match the part number from your original module exactly. While several part numbers may be compatible or supersede each other, a direct match is the safest way to ensure full functionality. Common part numbers include 84413406, 84668673, and the superseding part 85144760.
• Inspect for Water Damage: Before purchasing, ask the seller for clear photos of the connectors. Look for any signs of corrosion, rust, or a white or green crusty buildup on the pins. Avoid any module that shows evidence of moisture.
• Purchase the Protective Shield: Do not install a replacement module without also installing the updated water shield (GM Part No. 84667409). This part is inexpensive and is the only way to prevent your replacement module from suffering the same fate.
• Why Used OEM is a Good Choice: A recycled OEM module that is clean and dry offers the same performance and quality as a new one. Given that the issue is water damage, a used module from a vehicle that did not suffer from the HVAC leak is just as reliable as a brand-new part, but at a fraction of the cost.

Programming and Installation Requirements

Does the ANC module need to be programmed?

Despite general warnings often seen with electronic modules, evidence strongly suggests that a replacement ANC module with a matching part number is plug-and-play for the 2019-2024 Buick Enclave. The official GM service bulletin (20-NA-025) for this exact repair details the replacement procedure and makes no mention of software programming. Furthermore, DIY repair videos show owners successfully swapping the module without any need for a dealer visit or special tools. The warnings you may see on seller sites are likely a general disclaimer for all electronic parts, but they do not appear to apply to this specific module replacement.

Replacement Overview

Replacing the ANC module is a straightforward job that can be done by a DIYer with basic tools.

1. Location: The module is located behind the center console, mounted low towards the front of the vehicle.
2. Access: It is most easily accessed from the passenger side footwell by removing a trim panel on the side of the center console.
3. Tools: You will typically only need a 10mm socket and a trim removal tool.
4. Procedure: After disconnecting the battery, remove the side trim panel. The module is held in by a few 10mm nuts. Disconnect the three electrical connectors (they have locking tabs that need to be released), unbolt the old module, and install the new one. Remember to place the new protective water shield on the mounting studs before installing the new module.

Cost to Replace a Buick Enclave ANC Module

Frequently Asked Questions (FAQ)