Joe and Ben from Shifting Metal tackle a repossessed 2016 Mercedes C-Class bought from BCA, overcoming a locked-out AdBlue system and a bricked engine control unit.
The 2.1-litre diesel saloon arrived with an “engine start not possible” warning. The team initially bypass-started the car by manually bridging the exposed contacts of the starter motor relay in the engine bay fuse box.
Scanning with a TOPDON tool revealed faults for AdBlue system tampering. However, an attempt to update the engine ECU firmware corrupted the software, bricking the module and preventing the tool from restoring its own backup.
Ben salvaged the situation by writing a backup file back to the ECU using an Autotuner tool. This restored communication, allowing the TOPDON tool to successfully apply the latest firmware to both the engine ECU and the AdBlue module.
Underneath, the team cleared out a heavily crystallised AdBlue injector nozzle using a screwdriver and brake cleaner. Further workshop inspections revealed a severely worn front suspension ball joint showing an inch of play.
