Mercedes Airbag System Fault
If you drive a Mercedes, you expect high performance, superior comfort and an overall enjoyable driving experience, right?
While this is true, unfortunately, like all vehicles, Mercedes’ are susceptible to the occasional fault.
A recent client brought their Mercedes C220 AMG to Cheltenham and Gloucester Autocentre with bonnet and airbag issues.
Thankfully, our technicians are Mercedes experts and were confident they could resolve the issue.
Located in Cheltenham, we’re your local independent Mercedes specialists. With over 40 years of expertise and a commitment to using only genuine Mercedes parts, you can trust us to provide a quality, first-time fix for your vehicle.
Need help with your Mercedes? Call our team today.
A Faulty Mercedes C220 AMG Sport
When our client brought their Mercedes C220 AMG to Cheltenham and Gloucester Autocentre, they reported issues with the bonnet and airbag systems. Their vehicle’s dashboard showed the “bonnet open warning light” and the “airbag warning light”, even though the bonnet was securely closed.
Pretty confusing, huh?
Our initial suspicion was that the vehicle’s software had a communication glitch, but we’d need to perform a deeper inspection to confirm this.
A full diagnostic test was performed to examine the problem more closely. As your local independent Mercedes experts, we have access to the same level of technical information as the main Mercedes dealerships.
The diagnostic test revealed the following fault codes:
- A207/B2207: Internal fault in the control unit
- A761/C240300: Fault in the right front reversible emergency tensioning retractor
- 520201/C120201: Malfunction in the A1 instrument cluster
- 520400/C120400: Communication error with the control unit central gateway
With the client’s C220 AMG bonnet confirmed as shut and all switches functional, our experts shifted focus to the airbag access control module, a critical component managing airbag deployment.
The airbag access control module receives signals from impact sensors to deploy airbags when needed. As you can imagine, a malfunction here could significantly compromise your safety.
Our technicians meticulously examined the airbag access control module, checking all power connections and groundings and ensuring network signals were intact.
After thorough testing, it was evident that the module itself was defective and required replacement to return the vehicle to full working condition.
Fixing the Airbag Access Control Module
Before we continued to fix the vehicle’s problem, our experts called the client to discuss our findings.
At Cheltenham and Gloucester Autocentre, we always keep you in the loop. We only begin working on your vehicle when you say so, and you’re in complete control throughout the process.
With the go-ahead from the client, we began by sourcing a replacement airbag access control module.
As your local Mercedes specialists, we are committed to using only genuine Mercedes parts or high-quality alternatives for all our repairs, ensuring you get the highest quality needed to keep your vehicle running like new.
Our team of Mercedes specialists replaced the faulty airbag control module with an authentic Mercedes replacement, but the task took an unexpected turn during the coding process. The new module initially failed to accept the coding due to an undetected fault—a complication that might have been missed by another garage.
This newly discovered fault indicated that the previous module had not been communicating effectively.
It turned out to be an issue with the pyrofuse, a safety device designed to disconnect in the event of a severe impact to prevent short circuits or fires. The fault appeared to have arisen from a prior battery replacement; the pyrofuse connector beneath the battery was damaged during the process and went unnoticed.
This damage caused the system to falsely register the car as having been in an accident, misleading the system to behave as if the airbags had been deployed.
After identifying the broken pyrofuse using Mercedes’ detailed wiring diagrams, our team procured a pyrofuse connector repair kit. They expertly integrated the new connector, successfully coded the module, and conducted a comprehensive retest to ensure everything was functioning as it should.
Thankfully, everything worked perfectly, and all of the fault codes and dashboard warnings had disappeared.
Cheltenham and Gloucester Autocentre – Your local Mercedes Garage
Our deep understanding of all things Mercedes, alongside our 15-step diagnostic process, ensures you receive the best possible servicing and repairs.
Our dedicated team of Mercedes specialists quickly identified our client’s issue, secured the necessary parts, and repaired the vehicle, returning it to the client within just three working days.
This efficiency saved our client time and kept the cost down by getting the job done right on the first attempt.
The client was delighted to have their Mercedes C220 AMG back in safe working condition with no more dashboard warnings. They were even happier to receive their vehicle back so quickly and to have better than dealership value.
Looking for help with your Mercedes? Call Cheltenham and Gloucester Autocentre today, and let our Mercedes specialists care for your vehicle.
