SMG CAN Bus Decoding

[S54B32]

0x43F 0x61 0x01 0x26 0x5B 0x7E 0x84 0xE4 0xFE
0x43F 0x61 0x01 0x46 0xB5 0x7E 0x84 0xE4 0xFE

[HeinrichG_V12]

eacmen Yes, it's really strange. I've saw this thing with "alive counter" and then "checksum" in the massage by rev eng of PT-CAN of my E66... but in E46?

Of course I've converted them to hex

Here is how my 0x43F message looks like:



And here is the cluster:

[eacmen]

eacmen Hmm, strange thing...

Check this out: https://www.ms4x.net/index.php?title..._ID_0x43F_EGS1 (scroll down to SMG2 0x43F). If I'm using this description of 0x43F is all okay, except gear display, the rest (drivelogic, programm and stuff) is perfect.

I've also tried to send your three messages over CAN to the cluster and the behaviour is the same, gear is not displayed.

Not sure why the cluster isn't working? There might be other CAN messages required to enable SMG in the cluster when it turns on.

Obviously my log above is in decimal format so you'll need to convert to binary.

[HeinrichG_V12]

eacmen Hmm, strange thing...

Check this out: https://www.ms4x.net/index.php?title..._ID_0x43F_EGS1 (scroll down to SMG2 0x43F). If I'm using this description of 0x43F is all okay, except gear display, the rest (drivelogic, programm and stuff) is perfect.

I've also tried to send your three messages over CAN to the cluster and the behaviour is the same, gear is not displayed.

[eacmen]

Hello guys,

in the moment I'm playing around with instument cluster from E46 M3. I'm able to control all the gauges over CAN except SMG gears display. I think my problem is CRC for displaying the gears... I'm not calculating this at the moment.

Does anyone have a LogFile from the E46 M3 or E46 with a SMG transmission that contains the CAN ID 0x43F?

Thank you very much!

There is no CRC. If you look at my post above the first byte of 43F is the gear. In that first byte the upper half is whether the gear is engaged or not, the second half is the actual gear number. 0 is neutral and 7 is reverse.

I have all this in my racecapture and its working great.

[HeinrichG_V12]

Hello guys,

in the moment I'm playing around with instument cluster from E46 M3. I'm able to control all the gauges over CAN except SMG gears display. I think my problem is CRC for displaying the gears... I'm not calculating this at the moment.

Does anyone have a LogFile from the E46 M3 or E46 with a SMG transmission that contains the CAN ID 0x43F?

Thank you very much!

[SliM3]

Don’t know if this helps at all but.....

SMG CAN Bus signals:

Engine Speed - transmitted twice to the SMG II control unit. One signal arrives via the SMG CAN, the other arrives via a hard wire from the DME.
Engine Coolant Temp - as needed
Engine Oil Temp - as needed
Intake Air Temp - as needed
PWG - used to calculate engine load
EDR Feedback Pots - provides throttle position information that is used during slip intervention
Wheel Speed - Signal from DSC. Detects vehicle speed and wheel slip in Auto-Mode and during down shifts in all modes to detect drag torque induced wheel slip.
Transverse Acceleration - Signal from DSC. Transmitted in Auto-Mode so up and down shifts are prevented during high speed cornering
Steering Angle - Signal from angle sensor. Monitors cornering and slip info
Cruise Status
Parking Brake - Affects gear engagement and vehicle operation
Door Contacts - Signal via K-Bus and CAN Bus for safety program initiation
Brake Light Switch - Brake pedal status for unlocking shift lock, brake detection, engine starting, downhill detection, clutch engagement while stopped

[eacmen]

No, that data is only possible over diagnostic line with request commands (normally comes from Inpa or tool32). The awron display works this way. Therefore it can show data like IAT or exhausttemp, which is never present on CAN bus. You would need a microcontroller that captures this data and stream it back on CAN bus for racedash application etc.

That's what I assumed. Thanks for confirming.


Sent from my iPhone using Tapatalk

[S54B32]

No, that data is only possible over diagnostic line with request commands (normally comes from Inpa or tool32). The awron display works this way. Therefore it can show data like IAT or exhausttemp, which is never present on CAN bus. You would need a microcontroller that captures this data and stream it back on CAN bus for racedash application etc.

[eacmen]

You are right, on B0 is current gear. On B2 is drivelogic. And there is also shift request in the message, aka „blinking“ gear in cluster. To understand better, read a bit about MSB and LSB. Then you will understand real quick the structure.

Yeah I got tired of doing the decimal to hex conversion in my head. There seems to be alot of data that is constantly changing on that pid even when smg is in idle state.

Any chance smg pump pressure and temps are broadcast on the cluster CAN bus? That would be nice to log.


Sent from my iPhone using Tapatalk

[S54B32]

You are right, on B0 is current gear. On B2 is drivelogic. And there is also shift request in the message, aka „blinking“ gear in cluster. To understand better, read a bit about MSB and LSB. Then you will understand real quick the structure.

[eacmen]

This is not the most useful format, but I logged PID 0x43f (decimal 1087) using race capture pro. I cycled from Neutral to First, Second, First, Then Neutral. This is the raw data:

Neutral:

[1087.0]: 64.0, 6.0, 1.0, 129.0, 123.0, 4.0, 0.0, 254.0,

First:

[1087.0]: 65.0, 1.0, 131.0, 61.0, 123.0, 132.0, 228.0, 254.0,

Second:

[1087.0]: 66.0, 2.0, 133.0, 73.0, 123.0, 132.0, 237.0, 254.0,

Seems like the first byte is gear and some kind of state. 64 (0x40) means neutral and and "in gear", during the shift to 1 that first byte changes to 1 then 65 (0x41). So I am thinking that the first half byte is state with &0x40 meaning in gear or not, and the second half of the byte is the gear either being selected or currently selected depending on what the first half of the byte says.

Can you shed any light into the structure of 0x43f @olza?

thanks!

[olza]

i parsed it all. 0x43f includes many useful info: Gong, Kupplung state, Gear, Longitudial Accel, dsc off+sport, shift status, kombi code, program and so on.

[nickpiper12]

Yes, any 0x43F info would be appreciated!

[olza]

i just need to transfer some variables inside DME program and link them in 0x43F message. seems it will be useful for all.
Martyn , look PM.