Audi & Lamborghini Body Control Module Failure (2011-2020): Programming, Water Damage & Replacement Costs
This guide covers the common failures, locations, and critical programming requirements for the Body Control Module in the Audi A6, A7, A8, S8, R8, and Lamborghini Huracan.
- This module is NOT plug-and-play. It requires professional programming (Component Protection removal) by a dealer or specialist after installation.
- The most cost-effective solution is to buy a used module and have your original module's data cloned onto it by a mail-in service.
- For A6/A7/A8/S8 models, failure is very often caused by water damage from a leaking windshield or sunroof drain, as the module is located in the driver's footwell.
- Symptoms of a bad BCM are widespread electrical issues, including battery drain, non-working lights and windows, and no-start conditions.
CRITICAL: Component Protection and Programming
Warning: This is not a plug-and-play part. All Audi and Lamborghini vehicles in this guide use a security system called Component Protection (CP). If you install a replacement Body Control Module (new or used), it will not be fully functional until the Component Protection is adapted to your vehicle. This procedure requires a dealer or a qualified specialist with online access to factory diagnostic tools like ODIS. Failure to do this will result in many electronic features not working and a "Component Protection Active" error.
Additionally, the BCM is linked to the vehicle's anti-theft immobilizer system. A mismatched module can prevent the car from starting. For these reasons, a simple DIY swap is not possible without planning for professional programming or cloning services.
Symptoms of a Failing Body Control Module
A failing BCM often creates a bizarre and frustrating collection of seemingly unrelated electrical problems. Because it controls so many different systems, its failure can mimic many other issues. The most common sign is multiple electrical systems failing at once.
🎬 Watch: Common symptoms of a failing Body Control ModuleCommon Failure Modes and Known Issues
Water Intrusion (A6, A7, A8, S8 Models)
For the sedans and sportbacks covered in this guide (A6, A7, A8, S8), the most common cause of BCM failure is water damage. The module, also known as J519, is located in the driver's side footwell, under the dashboard and above the pedals. Clogged sunroof drains or a leaking windshield seal can allow water to drip directly onto the module's casing and connectors. This leads to corrosion on the circuit board, causing short circuits and eventual failure. If you are experiencing BCM symptoms in one of these cars, inspecting the module for signs of moisture or corrosion (a white or greenish powder) is a critical first step.
Vehicle-Specific Module Locations
- 2011-2018 Audi A8, 2013-2018 Audi S8, 2016-2018 Audi A6 & A7 Quattro: The BCM (J519) is located under the driver's side dashboard, above the pedals. Access requires removing the lower dash trim panel. 🎬 See this walkthrough for removing the J519 BCM1 module
- 2017-2020 Audi R8: The BCM is located in the passenger's footwell, above the fuse box.
- 2017-2020 Lamborghini Huracan: Sharing a platform with the R8, the BCM1 is also located in the front of the vehicle, likely in the passenger footwell. It is sometimes referred to as being in the vehicle's "e-box".
Associated OBD-II Trouble Codes
A failing BCM will not always trigger a check engine light, but it will store fault codes. A standard OBD-II scanner may not be able to read them. You will need a more advanced scan tool (like VCDS by Ross-Tech) that can communicate with all of the vehicle's modules. Common codes include:
- U-Series Codes (Network Communication): Codes like
U0141 - Lost Communication With Body Control Moduleare a strong indicator that the BCM has failed or is offline. - B-Series Codes (Body): These codes point to specific functions controlled by the BCM, such as lighting or lock circuits.
- 00003 - Control Module Defective: A common fault code stored within the BCM itself, indicating an internal hardware or software failure.
Pro Tip: Before condemning the BCM, always check the vehicle's battery and charging system. A weak or failing battery can cause low voltage, which can lead to a wide range of electrical issues that mimic BCM failure. Many forum users have reported that replacing an old battery resolved their electrical gremlins.
Buying a Used Body Control Module
Purchasing a used BCM is a cost-effective option, but requires careful consideration due to the programming requirements.
- Verify the Part Number: Match the OEM part number from your original module exactly. Part numbers may have several revisions (e.g., ending in EK, GB, GK). A newer revision is often compatible with an older one, but always confirm with the seller.
- Inspect for Physical Damage: Closely examine the photos of the used part. Look for any signs of corrosion on the connectors, which indicates past water damage. A water-damaged module may not be repairable or cloneable. Do not buy a module with any visible corrosion.
- Plan for Programming: A used BCM will not work without being programmed. You have two main options:
- Cloning Service: This is the best option. You send your original module and the used replacement to a specialist service. They will transfer the coding, VIN, and security data from your old module to the new one. This makes the replacement module plug-and-play, with no dealer visit required. This service typically costs between $100 and $300.
- Dealer Programming: You can have the used module installed and then take the vehicle to an Audi/Lamborghini dealer or a European auto specialist to have the Component Protection removed. 🎬 Watch: How to adapt Component Protection using ODIS software This will likely cost more than cloning.
Replacement Cost Comparison
The total cost of replacement involves the part itself, labor to install it, and the crucial programming/cloning service.
| Item | Estimated Cost |
|---|---|
| New OEM Module | $650 - $900 |
| Used OEM Module | $50 - $150 |
| Shop Labor (Physical Swap) | $150 - $300 (1-2 hours) |
| Dealer Programming (Component Protection) | $250 - $500 (1-2 hours labor) |
| Cloning Service (Mail-in) | $100 - $300 |
Cost Scenarios:
- DIY with Used Part & Cloning: $50 (Part) + $150 (Cloning) + Shipping = ~$225-$250
- Shop Install with Used Part & Cloning: $50 (Part) + $150 (Cloning) + $225 (Labor) = ~$425
- Shop Install with New OEM Part & Dealer Programming: $750 (Part) + $225 (Labor) + $375 (Programming) = ~$1350+
Frequently Asked Questions (FAQ)
Can I replace the Body Control Module myself?
The physical replacement is possible for an experienced DIY mechanic, as it mainly involves removing interior trim panels in the footwell. However, the module will not function correctly until it is programmed. You must arrange for either a mail-in cloning service or a visit to a dealer/specialist for programming after installation.
What is the difference between BCM1 and BCM2?
These vehicles often have two body control modules. The part covered in this guide (4H0907063xx) is the BCM1 (J519), located in the front of the car, which controls lights, windows, and other convenience features. The BCM2 is typically located in the trunk and is the master module for the immobilizer, keyless entry, and Component Protection. While you may be replacing the BCM1, the BCM2 is what makes dealer-level programming necessary.
Will a used BCM from the exact same car model work without programming?
No. The BCM is tied to the specific VIN of the car it came from through Component Protection. Even if the donor car is identical, the module will have restricted functionality until it is adapted to your car's VIN by a professional.
My mechanic says my BCM is bad due to water damage. Can it be repaired?
Sometimes, yes. If the corrosion is not too severe, a specialist electronics repair service may be able to clean the board and replace damaged components. However, if the damage is extensive, replacement is the only option. If you plan to clone the module, the original one must be in a condition where its data can still be read.
Helpful Videos
Technical Specifications
OEM Part Numbers: 4H0907063EK 4H0907063GB 4H0907063JK 4H0907063DM 4H0907063GK 4H0907063GM 4H0907063AM
Also known as the Onboard Supply Control Module or J519. Controls body electronics and communicates via CAN bus. Subject to Component Protection security.
We Have This Part in Stock
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.
- Audi S8:
- Audi R8:
- Audi A8 Quattro:
- Audi A6 Quattro:
- Lamborghini Huracan:
- Audi A7 Quattro:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- CRITICAL: Component Protection and Programming
- Symptoms of a Failing Body Control Module
- Common Failure Modes and Known Issues
- Associated OBD-II Trouble Codes
- Buying a Used Body Control Module
- Replacement Cost Comparison
- Cost Scenarios:
- Frequently Asked Questions (FAQ)
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