2017-2020 Audi Q7 & Bentley Bentayga Air Bag Module: Crash Data, Programming, and Replacement Guide

Symptoms of a Bad Air Bag Control Module

The most common and serious symptom of a failing air bag control module is a continuously illuminated airbag or SRS warning light on your instrument cluster. This light indicates that a fault has been detected in the safety system, and as a result, the entire system is deactivated. This means that in the event of an accident, your airbags and seatbelt pretensioners will not deploy. A vehicle with an active SRS warning light will not pass a safety inspection in most states.

Other, less common symptoms can include:

• Unusual clicking sounds coming from behind the dashboard.
• Intermittent electrical issues, such as other warning lights appearing randomly.
• A diagnostic scan tool being unable to communicate with the airbag module (address 15 in VCDS/VAG-COM).

It is important to note that the airbag light can also be triggered by faults in other parts of the system, like a bad crash sensor, a faulty clockspring, or a wiring issue. A full diagnostic scan with a capable tool is necessary to confirm the problem is with the control module itself.

Common Diagnostic Trouble Codes (DTCs)

When scanned with a VAG-specific tool like VCDS, a faulty module may show codes indicating an internal fault or communication error. Common codes pointing to a module issue include:

• B1000 / B1126 / B1145 (and similar): Airbag ECU Malfunction.
• U1017 / U1113: Function Restriction due to Faults in Other Modules or lost communication.
• Codes indicating "Crash Data Stored" or "Deployment Commanded," which mean the module has locked after an impact and must be reset or replaced.
• 01221 / 01222: Faults related to crash sensor basic settings, which can sometimes point to a module that needs re-coding.

Known Issues, Recalls, and Technical Service Bulletins (TSBs)

Both the Audi Q7 and Bentley Bentayga have been subject to recalls related to the airbag system. While not always a direct failure of the control module itself, these issues are critical for owners to be aware of.

2017-2020 Audi Q7

• Software Update Recall (SAGA 69O3): Some 2017 Q7 models were recalled for a software issue in the airbag control module that could cause the frontal airbags to deploy with excessive force in certain crashes. The fix was a software update performed by the dealer.
• Side Airbag Recall: Certain 2019 Q7 vehicles were recalled because the side curtain airbags might not inflate properly during a crash. The remedy involves replacing the affected side curtain airbags.
• Seat Belt Pretensioner Recall: A recall was issued for some 2017 Q7s because the seat belt pretensioners might not activate correctly in an accident. The fix is to replace the pretensioner units.

2018-2020 Bentley Bentayga

• Side Airbag Recall (NHTSA 20V092000): Affecting 2018-2020 models, this recall addresses an issue where side curtain airbags may not inflate properly, increasing the risk of injury. The fix is a replacement of the curtain airbags by a dealer. This issue is very similar to a recall affecting the Audi Q7.

Buying a Used Air Bag Control Module

Purchasing a used airbag module can be a cost-effective solution, but it comes with critical requirements. Failure to follow these steps can result in a non-functional part and a compromised safety system.

The #1 Warning: Crash Data

If a vehicle is in a collision that causes an airbag or seatbelt pretensioner to deploy, the module permanently records "crash data." This data locks the module, rendering it useless until it is professionally reset. A module with stored crash data will cause the airbag light to stay on and will not command deployment in a future accident.

• A used module MUST be certified as "reset" or cleared of all crash data. Reputable sellers will explicitly state this.
• Do not purchase a module from a collided vehicle without proof of a professional reset. A standard OBD-II scanner cannot clear this hard-coded data.
• Services exist that can reset your original module or a used one for a fee, which is often the most reliable option.

Programming and Component Protection

A new airbag module from the dealer comes "blank" and must be coded to your vehicle's specific VIN and equipment list (e.g., number of airbags, sensor types). A used module, even if reset, was coded to its original vehicle. It will likely need to be re-coded to your car using a tool like VCDS or the dealer's ODIS system.

Pro Tip: The easiest path is often to have your vehicle's original module sent out for a reset service. Since it is already coded to your VIN, it will be plug-and-play upon reinstallation, with no extra programming required.

Part Number Compatibility

The Audi Q7 and Bentley Bentayga share the same family of airbag control modules. However, you must match the part number exactly. The primary part number is 4M0959655A, but several suffix variations exist, such as 4M0959655F and 4M0959655G. Check the number on your original module before ordering a replacement.

Replacement Overview

Replacing the airbag module in the Audi Q7 and Bentley Bentayga is a labor-intensive job best left to experienced technicians. The module is located deep under the center console, requiring the removal of trim, the armrest, and other components to gain access.

Due to the complexity of accessing the module and the absolute necessity of proper programming, this is not considered a beginner-friendly DIY job. While a skilled DIY mechanic can perform the physical swap, the final coding step requires specialized tools and knowledge.

Cost Comparison

Prices can vary significantly based on your location and chosen repair path.

Frequently Asked Questions (FAQ)