HGS’s mega macs allows diagnostics on Mercedes-Benz vehicles with access protection


The connectivity functions in modern vehicles bring a host of benefits, but can also pose a risk in terms of tampering and unauthorised access to data. This is why vehicle manufacturers (VMs) are working on cyber security systems to make it more difficult to use the on-board diagnostics (OBD) interface to access data, and also be used to grant access via different authorisation levels.

After Fiat Chrysler Automobiles (FCA) launched its Security Gateway (SGW) to protect the company’s vehicles against unauthorised access, Mercedes-Benz AG followed suit by introducing a two-stage security concept. Depending on the model and the date of the car’s production (2019 or later), the electronic ignition lock control unit now features a partial access restriction which uses seed-key security. Diagnostic devices that do not request a random number generated by the vehicle and are unable to respond correctly using the matching decryption algorithm will only be able to perform basic operations, such as reading and deleting fault codes.

The good news is that workshops that update the software on their HGS mega macs to version 59 can continue to run the tried and trusted diagnostics operations and perform basic settings and calibrations in these secured vehicles without any further action. The unlocking of the mega macs takes place in the background, unnoticed by the user, and aregistration at the vehicle manufacturer’s original equipment (OE) portal is not necessary.

By integrating the seed-key security process into the current mega macs software, HGS has taken a second step towards enabling independent workshops to continue diagnostics and repair as normal. The first step was the launch of the SGW adapter for FCA vehicles in spring 2020.

Several other VMs are currently planning similar security measures, so HGS has decided to implement full cyber security management in the mega macs software as part of a third step in late 2020. Depending on the car manufacturer’s security systems, this OE-compliant integration will enable users to contact different manufacturer portals in order to obtain licenses for activation directly from the mega macs. The aim is to provide independent workshops with a convenient multi-brand solution and enable them to compete effectively in the marketplace.