CAN Bus database

CAN bus mappings by OEM ECU and aftermarket device

OEM ECUs (Non OBD-II protocol)

BMW E46

Installation instructions

  • Baud Rate: 500K
  • Little Endian Format
BMW E46 (including M3)
Channel Units CAN Id Offset (bytes) Length (bytes) Conversion Notes
TPS % 809 6 1 (B6 / 255)
EngineTemp C 809 2 1 (B2 * 0.75) - 48.373 Convert to Farenheight: (temperatureC * 1.8) + 32
OilTemp C 1349 5 1 B5 - 48.373 Convert to Farenheight: (temperatureC * 1.8) + 32
RPM 790 3-4 1 ((B4 * 256) + B3) / 6.4

Mini Cooper R53

Installation instructions

  • Baud Rate: 500K
  • Little Endian Format
Mini Cooper R53
Channel Units CAN Id Offset (bytes) Length (bytes) Conversion Notes
TPS % 809 6 1 (B6 / 254) * 100
EngineTemp C 809 2 1 (B2 * 0.75) - 48.373 Convert to Farenheight: (temperatureC * 1.8) + 32
RPM 790 3-4 1 ((B4 * 256) + B3) / 6.4

Aftermarket ECUs

Motec M84

  • Standard Channel Mapping for Motec M84 ECU
  • Big Endian (MSB) data format
Motec M84
Channel Units CAN Id Offset (bytes) Length (bytes) Multiplier Adder Notes
RPM RPM ? 0 2 1 0
TPS % ? 2 2 1 0
MAP kPa ? 4 2 1 0
AIT C ? 6 2 1 0
EngineTemp C ? 8 2 1 0
AFR Lambda ? 10 2 1 0
FuelPress kPa ? 20 2 1 0
OilPress kPa ? 24 2 1 0
Speed? (Dig In 1 Speed?) ? 52 2 1 0 Need to verify this field
InjDutyCyc % ? 110 2 1 0

Megasquirt CAN ( MS2/MS3/MS3 Pro )

Installation instructions


Megasquirt CAN (Dashboard Mode)
Channel Units CAN Id Offset (bytes) Length (bytes) Multiplier Adder Notes
MAP kPa 1512 0 2 0.1 0 Manifold Absolute Pressure
RPM 1512 2 2 1 0
Coolant F 1512 4 2 0.1 0
TPS % 1512 6 2 0.1 0
MAT F 1513 4 2 0.1 0 Manifold Air Temperature
AFR 1514 0 1 0.1 0
Megasquirt CAN (standard mode)
Channel Units CAN Id Offset (bytes) Length (bytes) Conversion Notes
RPM RPM 1520 6 2 (B6 * 256) + B7
IgnTiming Degrees 1521 0 2 ((B0 * 256) + B1) / 10
AFR AFR 1521 4 2 ((B4 * 256) + B5) / 10 Legacy AFR1 (Deprecated on MS3) - to use AFR2 specify offset 6
MAP kPa 1522 2 2 ((B2 * 256) + B3) / 10
MAT F 1522 4 2 ((B4 * 256) + B5) / 10
EngineTemp F 1522 6 2 ((B6 * 256) + B7) / 10
TPS % 1523 0 2 ((B0 * 256) + B1) / 10
EngineTemp F 1522 6 2 ((B6 * 256) + B7) / 10
Knock % 1524 0 2 ((B0 * 256) + B1) / 10 Indication of knock input
AFR % 1551 0 1 B0 / 10 AFR for cylinder #1 (MS3+ compatible) - add 1 to offset for subsequent AFR inputs

MBE Systems 992

Installation instructions

  • Baud Rate: ???
  • Little Endian format
MBE Systems 992 (Locked Caterham mode)
Channel Units CAN Id Offset (bytes) Length (bytes) Conversion Notes
EngineTemp C? 814 0 1 B0 Need to verify scaling and temperature units
RPM RPM 814 1 2 (B2 * 256) + B1
TPS % 814 3 0 B0 / 5.0 Outputs as throttle voltage. assuming a 0-5v system, scale by 5v
OilPress PSI? 815 2 1 B2 Need to verify scaling and Pressure units
OilTemp C? 815 3 1 B3 Need to verify scaling and temperature units

Tire Pressure Monitoring Systems (TPMS)

Brightwater Technologies (WIP)

Brightwater TPMS
Channel Units CAN Id Offset (bytes) Length (bytes) Multiplier Adder Notes
TirePres_RF PSI 1440 2 2 0.01 0
TireITmp_RF C 1440 3 1 0 -40 Internal Tire Temperature
TirePres_LF PSI 1441 2 2 0.01 0
TireITmp_FL C 1441 3 1 0 -40 Internal Tire Temperature
TirePres_RR PSI 1442 2 2 0.01 0
TireITmp_RR C 1442 3 1 0 -40 Internal Tire Temperature
TirePres_RL PSI 1443 2 2 0.01 0
TireITmp_RL C 1443 3 1 0 -40 Internal Tire Temperature

Cameras

AIM Smarty CAM CAN protocol

Installation instructions

  • Baud Rate: 1MB
  • Values in little endian format
AIM Smarty CAM protocol
Channel Units CAN Id Offset (bytes) Length (bytes) Multiplier Adder Notes
RPM RPM 1056 0 2 1 0
EngineTemp C 1056 6 2 0.1 0
OilTemp C 1057 4 2 0.1 0
OilPress Bar 1057 6 2 0.01 0
TPS % 1058 2 1 1 0
Fuel L 1070 0 1 1 0