BMW’s newest diesels moved from the DDE8 to the DDE9 generation in 2022 and 2023. The four-cylinder 18d, 20d and 23d mild hybrids run the Bosch MD1CS015; the six-cylinder 30d and 40d mild hybrids run the MD1CS115. Both are TC399 units with a new level of protection, and both were closed to every tool until mid-July.
Autotuner now reads and writes them on the bench after a mail-in unlock: three and a half minutes to read, thirty seconds to write, checksums and a full backup included. Once the ECU has been unlocked it stays unlocked, so a Stage 2 or an option later is a same-day bench job.
Cars this opens up
- Four-cylinder (MD1CS015): BMW 2 Series Active Tourer (2022 on), 5 Series (2023 on), X1 (2023 on), X2 (2023 on) in 18d, 20d and 23d MHEV; Mini Countryman 2.0d MHEV (2024 on)
- Six-cylinder (MD1CS115): BMW 5 Series (2023 on), 7 Series (2023 on), X5 (2023 to 2027), X6 (2023 on), X7 (2023 on) in 30d and 40d MHEV
What it means
The 520d and X1 20d are two of the most common cars in our diary, and for a year the 2023-on versions had to be turned away. A Stage 1 on the B47 20d is typically worth around 40 PS and 80 Nm; on the B57 30d around 50 PS and 100 Nm, and the 40d more. The car keeps its mild hybrid system and its economy; the difference is in the mid-range where you feel it towing or overtaking.
Owners: put your registration into the tuning builder for the exact figures and price. Dealers: DDE9 files go through the file service like any other BMW, and the Autotuner is the tool that reads them today.
