CAN bus mappings by OEM ECU and aftermarket device
Megasquirt CAN ( MS2/MS3/MS3 Pro )
Installation instructions
| Megasquirt CAN
|
| 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
|
BMW E46
Installation instructions
| 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
|
|
