Overview
Twin-turbo predecessor to the N55. Loves boost, hates its own injectors and high-pressure fuel pump.
Common models
E82 135i; E90/E91/E92 335i; E60 535i; E89 Z4 35i; E70 X5 35i.
Supported live-data parameters
Beemuu’s N54 profile reads 12 parameters from the engine control module. 11 are marked verified — sourced from the OBDb DID database and confirmed against the project’s own OBDb-verified community data set. The remaining parameters are seeded from standard OBD-II PIDs or marked as BMW-specific but pending real-car verification.
Each parameter has a query path (either an OBD-II PID like obd:0C or a BMW-specific identifier) and a decoder (how raw bytes are converted to engineering units). The full schema is documented in docs/DECODE_FUNCTIONS.md.
| Parameter ID | Label | Unit | Query path | Decoder | Status |
|---|---|---|---|---|---|
rpm | Engine speed | rpm | obd:0C | u16_quarter | ✓ verified |
coolant | Coolant temp | °C | obd:05 | temp_u8 | ✓ verified |
oil | Oil temp [UNVERIFIED placeholder] | °C | local:10 | temp_u8 | ⚠ unverified |
iat | Intake air temp (post-IC) | °C | obd:0F | temp_u8 | ✓ verified |
map | Manifold pressure (abs) | kPa | obd:0B | u8 | ✓ verified |
baro | Barometric pressure | kPa | obd:33 | u8 | ✓ verified |
rail | Fuel rail pressure (HPFP) | kPa | obd:23 | u16_times10 | ✓ verified |
load | Engine load | % | obd:04 | percent_a | ✓ verified |
throttle | Throttle position | % | obd:11 | percent_a | ✓ verified |
speed | Vehicle speed | km/h | obd:0D | u8 | ✓ verified |
volt | Module voltage | V | obd:42 | u16_milli | ✓ verified |
ambient | Ambient temp | °C | obd:46 | temp_u8 | ✓ verified |
Common N54 faults worth scanning for
Direct-injection high-pressure fuel pump failures (HPFP); index-12 injector failures; charge-pipe blow-off under boost; wastegate rattle on cold start; turbocharger oil-line leaks.
For BMW-specific fault codes that come up on the N54, see the DTC index — particularly the fuel-pressure, VANOS and boost-pressure families. The project’s community opinions have per-code repair paths contributed by owners and indie technicians.
N54 questions
What is the N54 engine?
Twin-turbo predecessor to the N55. Loves boost, hates its own injectors and high-pressure fuel pump.
How do I connect Beemuu to a N54 car?
KWP2000 is the standard. E-series N54 uses KWP2000 over K+DCAN; F/G-series N54 uses UDS over DoIP via an ENET cable.
What live-data parameters does Beemuu read?
12 parameters; 11 verified, the rest seeded and pending real-car validation.
What should I check first?
Direct-injection high-pressure fuel pump failures (HPFP); index-12 injector failures; charge-pipe blow-off under boost; wastegate rattle on cold start; turbocharger oil-line leaks.