If your Mercedes Vito or Viano (W447) won’t start, and diagnostics show the error:
B17F F00 – Steering Column Lock Actuation Signal Improbable,
Then the issue is likely caused by a fault in the Electronic Ignition Switch (EIS) or Steering Lock (ESL) – part of the advanced Mercedes FBS4 anti-theft system.
At Mr. Ignition, we specialise in professional ignition switch diagnostics and repairs, offering a secure and fast postal service to get you back on the road without costly dealer delays. Prices start from £249.
Vehicles Covered
This repair service is designed specifically for the following models:
- Mercedes-Benz Vito W447
- Mercedes-Benz Viano
- Mercedes-Benz Metris (USA/Canada)
Understanding FBS4 and EIS Failures
The FBS4 system (introduced by Mercedes around 2015) links key security components such as the EIS, ESL, ECU, and vehicle keys using encrypted data. When a failure occurs in this chain, often due to internal wear or steering lock malfunction, the vehicle becomes immobilised and unresponsive, even if the key physically turns.
Symptoms of FBS4 Ignition Module Faults
- Key turns in the ignition, but there’s no response
- Instrument cluster remains blank
- Vehicle won’t crank or start
- Clicking from the steering lock, or no sound at all
- DTC: B17F F00 stored in control module
Mercedes EIS Part Numbers We Commonly Repair
We accept a range of W447 EIS units with part numbers such as:
- A4479004805
- A4479007606
- A4479001111
- A4479004505
- A4479000911
- A4479002805
- A4479007306
- A4479002505
- A4479007313
If your part isn’t listed, please get in touch with us to check availability.
How Our Postal Service Works
- Remove the EIS module from your vehicle and package it securely.
- Include your vehicle’s VIN and all current keys.
- Send it to Mr. Ignition using a tracked courier or Royal Mail service.
- We’ll carry out a complete diagnostic, repair, and reprogramming service within 1 to 3 working days.
- Your repaired unit will be shipped back fully functional, plug-and-play.
Why Mr. Ignition?
- Independent specialists in ignition and steering lock systems
- Skilled in FBS4 and dealer-level module repairs
- Rapid turnaround – typically 1 to 3 business days
- 6-month parts and labour warranty included
- Secure postal service covering all of the UK
- No hidden fees – prices from £249
Get in Touch
For advice, booking, or to arrange a repair:
Phone: 07921 365 247
Website: www.mrignition.co.uk
Email/WhatsApp: Available via the same number