BMW B48 2.0 Turbo: Specs, Engine Codes, ECUs & Maintenance
BMW · Engine information · U.S. & Canada
B48
2.0 turbo · One family, several distinct versions
The B48 is more than a single 2.0-litre specification. Longitudinal 30i engines and transverse M35i versions use different installations, output levels and controllers, making the full engine code especially useful.
Engine versions
- B48B20O0
- Original longitudinal · typically 248 hp
- B48B20O1
- Updated longitudinal · 255 hp / 295 lb-ft
- B48A20T1
- Transverse M35i · 301–302 hp / 332 lb-ft
- Compression
- 11.0:1 O0 · 10.2:1 O1 · 9.5:1 T1
- Construction
- Aluminium inline-four · 16 valves
- Engine-code layout
- A = transverse · B = longitudinal
Fuel & airflow
- Injection
- Direct · up to 350 bar on TU
- Valve control
- Valvetronic + double VANOS
- Boost control
- Electronic wastegate
- Charge cooling
- Liquid-cooled on listed TU versions
- M35i hardware
- Larger turbo and reinforced rotating assembly
- Cam drive
- Chain · revised for TU
Engine controllers · Bosch MEVD17 and MG1 variants
Installation and revision determine the controller. The same B48 family can carry an MEVD17 or an MG1 DME, and the BMW DME number further distinguishes the vehicle architecture. A matching family name does not make software interchangeable.
| Controller | Applications & timing | Technical distinction |
|---|---|---|
| MEVD17.2.3 | Original transverse B48A20 applications | TC1793; early transverse injection, boost and Valvetronic control. |
| MG1CS003 · DME 8.4.1 / 8.4.0 | Original longitudinal B48B20 in F-series / G-series | MPC5777; BMW designation differs with vehicle architecture. |
| MG1CS201 · DME 8.4.T0 | Updated longitudinal B48B20M1/O1 | TC298; technical-update fuel and thermal-management strategies. |
| MG1CS201 · DME 8.4.T1 | Updated transverse B48A20, including M35i T1 | TC298; transverse installation and high-output calibration. |
Read the engine designation, Bosch label and diagnostic software identifiers together. Canadian and U.S. 30i vehicles may use B48 or the related B46 according to build and emissions certification.
Selected U.S. & Canadian vehicles
| Model | Chassis | Model years | Engine / factory output |
|---|---|---|---|
| 330i / Z4 sDrive30i | G20 / G29 | 2019–2022 | B48B20O1-equipped builds · 255 hp / 295 lb-ft |
| X2 M35i | F39 | 2019–2023 | B48A20T1 · 302 hp / 332 lb-ft |
| M235i xDrive Gran Coupe | F44 | 2020–2024 | B48A20T1 · 301 hp / 332 lb-ft |
Selected North American B48 applications only. Confirm the engine on 30i models; this table does not assign B48 to every vehicle carrying that badge.
Common issues & key risks
Oil-filter-housing leaks. The housing and its seals can lose coolant or oil. Pressure-test low coolant levels and inspect the housing beneath the intake before replacing unrelated cooling parts.
Coolant vent line. The cylinder-head quick connector can break on affected earlier applications. BMW issued a service action for specified 2015–2018 builds; check the VIN and repair history.
Pump & heat-management module. Pump seals can leak, while the coolant-control module can leak or stick. Temperature warnings and coolant-control faults need diagnosis before sustained load.
EVAP purge valve. A faulty tank-vent valve can trigger an engine warning and uneven running. BMW lists component coverage for eligible applications; confirm the diagnosis and VIN eligibility.
Misfires & ventilation. Check plugs and coils for load-related misfires. Whistling or abnormal oil use calls for a crankcase-pressure test, rather than assuming turbo failure.
Keep it consistent: Use the exact BMW oil approval for the vehicle. Let oil temperature stabilize before high load and investigate coolant loss immediately.
References
| Topic | Source |
|---|---|
| Design and variants | BMW B46TU/B48TU technical training |
| M35i specifications | BMW USA: 2019 X2 M35i |
| M235i specifications | BMW USA: 2020 2 Series Gran Coupe |
| Filter-housing failure | FCP Euro · housing failure modes |
| Cylinder-head vent line | BMW SI B17 01 21 |
| Cooling-system repairs | FCP Euro · shared B48/B58 cooling components |
| Purge-valve coverage | BMW SI B01 02 24 · reproduced bulletin |
| Photograph | BMW B48B20 engine installed in a BMW 125i. Photo: Thilo Parg / Wikimedia Commons · CC BY-SA 4.0. Resized. |
Model years refer to selected U.S. and Canadian applications. Equipment and software vary by build. Use current BMW service information for diagnosis and repair.
