Bosch MD1CS015 / MD1CS115: BMW’s MHEV diesel finally unlocked

Two separate control units depending on engine capacity:

MD1CS015: controls the B47 MHEV 4-cylinder diesel engines: the 18d, 20d and 23d engines. These are economical and versatile versions fitted to compact models and entry-level 5 Series models.

MD1CS115: controls the B57 MHEV inline 6-cylinder diesel engines: the 30d and 40d engines. The backbone of the most well-balanced 5 Series, 7 Series, X5, X6 and X7 models, combining power, torque and fuel economy in a single unit.

Both control units share the same access procedure and the same level of protection.

4-cylinder B47 MHEV diesel engine (MD1CS015)

MHEV diesel engines now account for the majority of BMW’s recent sales in Europe. Every 5 Series G60 530d, every X5 40d and every X7 sold since 2023 is fitted with one of these two control units. With a single update, a massive proportion of the current BMW fleet therefore becomes accessible via Shiftech.

The factory mapping for these mild-hybrid diesel engines, as with all mass-produced vehicles, incorporates margins relating to type-approval standards, warranty durability and fuel variations across different markets. Remapping allows these margins to be utilised: torque is available earlier in the rev range, acceleration is more responsive, and the driving experience finally matches the true potential of this diesel engine.

The process is carried out in two stages:

1. Mail-in Unlock: your ECU is sent to Autotuner’s engineers for secure unlocking, without the need to physically open the unit
2. Bench Reprogramming: once the unit is back in the workshop, full access is granted. The original mapping is backed up before any work begins. The unit can be restored to its original settings at any time.

This procedure is carried out only once per ECU.