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Retrofitting C117 Canbus-B Interfacing seats and controller
Hi All,
I have a project (with no canbus) where im planning on using my spare C117 seats from my CLA200. The seat controls for these are on the door, I believe it's still using the same Canbus-B (interior).
Would it be possible to connect the 2 can bus wires on each device (door switch and seat) together to control movements, obviously need to get 12v to the seat and power the door switch also. If not what would new the best way to achieve an outcome to control the seats?
I can rewire the motors just with manual switches but I would like to retain the seat controllers as I believe they have limit switches etc.
I have a project (with no canbus) where im planning on using my spare C117 seats from my CLA200. The seat controls for these are on the door, I believe it's still using the same Canbus-B (interior).
Would it be possible to connect the 2 can bus wires on each device (door switch and seat) together to control movements, obviously need to get 12v to the seat and power the door switch also. If not what would new the best way to achieve an outcome to control the seats?
I can rewire the motors just with manual switches but I would like to retain the seat controllers as I believe they have limit switches etc.
Cheers Ben
it's German... its more complicated than we think
They use no limit switches, the limits are learned dynamically by software.
On your private local bus you'll need to add termination resistance 100R (or 60R or 120R).
🤞
it's German... its more complicated than we think
They use no limit switches, the limits are learned dynamically by software.
On your private local bus you'll need to add termination resistance 100R (or 60R or 120R).
🤞
thats super helpful. thank you.
On the seats I believe
Pin 29: CAN B H
Pin 30: CAN B L
I also dont have a wiring diagram, just a few bits and pieces. Where would I add the terminating resistor/s? In hope I wired the can bus on the switch directly to the seat with no success.
Im not sure that the seat is going to be providing the power also required for the switch to work and I may need to inject with some sort of transceiver or what not.
I also dont have a wiring diagram, just a few bits and pieces. Where would I add the terminating resistor/s? In hope I wired the can bus on the switch directly to the seat with no success.
Im not sure that the seat is going to be providing the power also required for the switch to work and I may need to inject with some sort of transceiver or what not.
this is a fun research topic, no guarantee of perfect success. Module CAN to CAN should work.
The CAN resistor are across both bus signals, nop because there are always in pair so GND to CAN +/-.
Each module needs to be powered up: +12V/GND.
My seat control with Memory module for DCU
The 3 wires output connector suggest this seat buttons module is a LIN, not CAN!
It is attached to DCU Module that connects data over CAN-B. That tells me you need to involve DCU as a LIN/CAN transceiver.
Once you have your module connected, you'll see if datagram between modules are co-operating???
this is a fun research topic, no guarantee of perfect success. Module CAN to CAN should work.
The CAN resistor are across both bus signals, nop because there are always in pair so GND to CAN +/-.
Each module needs to be powered up: +12V/GND.
My seat control with Memory module for DCU
The 3 wires output connector suggest this seat buttons module is a LIN, not CAN!
It is attached to DCU Module that connects data over CAN-B. That tells me you need to involve DCU as a LIN/CAN transceiver.
Once you have your module connected, you'll see if datagram between modules are co-operating???
You're dead right and in this instance.. that sucks. Was hoping the door switch was just CAN and didnt rely on the DCU. Not sure where to go now as I dont have A DCU and already bought door switches. If I get a DCU and it works then great, but if it doesn't ill have a full set of DCU and switches that aren't going to do much good.
Im thinking out aloud here but if the seat module has LIN, possibly for the lumbar switch could I interface with that or is the DCU getting the inputs from the seat switch and then spitting them out as CAN messages.
If I could get a pinout for both the seat switch, SCU and potentially DCU it would make life a whole lot easier
Last edited by bawbanksy; Mar 3, 2024 at 05:56 PM.
yeah, I think you're starting to see some light. The modules firmware code does what it does and we know flexibility and open stack are not built-in.
As much as I like hooking up buttons directly to the seat, I don't think the seat controller is going to query around for inputs.
We don't know much about proprietary hardware and even less about their source code features.
I feel you best shot is to cutout this system around pieces you can reuse as is. Include DCU and you may have a good chance at commanding the matching seat controller, right?
yeah, I think you're starting to see some light. The modules firmware code does what it does and we know flexibility and open stack are not built-in.
As much as I like hooking up buttons directly to the seat, I don't think the seat controller is going to query around for inputs.
We don't know much about proprietary hardware and even less about their source code features.
I feel you best shot is to cutout this system around pieces you can reuse as is. Include DCU and you may have a good chance at commanding the matching seat controller, right?
Makes sense, will keep an eye out for a cheap DCU to try.
DCU's are arriving today. Its just a standard 120ohm resister I need right?
Good luck with progress today
120Resistor used to be the CAN legendary termination resistors at either ends.... now it's changed to a single pair of 60R at the distribution bars.
I would use 100R to GND from both CAN+/- lines.
This is used to bias a reference so output voltage levels don't float openly. You don't need extremely exact values.
🤞
Last edited by CaliBenzDriver; Mar 5, 2024 at 08:38 PM.
It works.... Seat switches plugged into DCU with can bus directly connected between DCU and SEATCU. It is possible
Is it at all possible to by connectors, looked on wis and epc but can't see anything. Need the main body to SCU connector (white) and a connector for the DCU?
Is it at all possible to by connectors, looked on wis and epc but can't see anything. Need the main body to SCU connector (white) and a connector for the DCU?
Congratulations
All sorts of connectors would be nice but for now soldering works... why don't you make your own pigtails with a pair of M/F connectors easily available where you like to shop.
No one is going to tell you, it's the wrong connector, right?
Ok perfect. Also thanks for the quick reply. So a 100ohm resistor on each can line right before they go into the seat control unit? I’m pretty decent with wiring, but canbus eludes me lol
Ok perfect. Also thanks for the quick reply. So a 100ohm resistor on each can line right before they go into the seat control unit? I’m pretty decent with wiring, but canbus eludes me lol
I did it on the door controller but I cant se why it won't work there. just try and see
I did it on the door controller but I cant se why it won't work there. just try and see
Ok tried that and it didn’t work, but I’m sure I most likely did the resistors wrong. Could you show or explain how you have yours attached to the system?
don't mind me asking why you are adding more resistors in the existing CAN.
I saw mine built-in the bus-bars near front thresholds.
One set is all that's necessary.
Instead of using TWO sets of 120R to end up in parallel as 60R... MB uses only ONE set of 60R at threshold.
That's Not really an active issue.
don't mind me asking why you are adding more resistors in the existing CAN.
I saw mine built-in the bus-bars near front thresholds.
One set is all that's necessary.
Instead of using TWO sets of 120R to end up in parallel as 60R... MB uses only ONE set of 60R at threshold.
That's Not really an active issue.
from what they are saying it may be needed because the seats aren’t going in a Mercedes, they’re going into a car without canbus. I’ve tried it with and without resistors and mine still does not work, so I’m still trying to figure it out.
from what they are saying it may be needed because the seats aren’t going in a Mercedes, they’re going into a car without canbus. I’ve tried it with and without resistors and mine still does not work, so I’m still trying to figure it out.
I seeee...., you are trying to recycle the seat + controller in a car without CAN-Bus and likely want this to work normally stand alone without networking.
I have not tried that but there's something there to be discovered I am sure.
In that case play with resistance, no functionality to loose. No CAN then
Any of you fellas still active? haha, came across this thread. Been struggling with this situation, puting CLA seats in an S14 240sx.. Tried switch to Door module to seat module no luck, tried wiring a SAM up with it all, not luck.. figured i need the Potential Distributor.. cant find any close or shipping reasonably soon... Orderd an arduino and the parts to build a can-bus or lin-bus system... then found this thread!
Is my below diagram what you're explaining? i'm going to try it tomorrow but was hoping somebody, anybodddddy, from this threads past would chime in. Thanks.. (ps if you didnt figure it out all the connectors are TE MQS, you can buy them on mouser or digikey, i can share part numbers if that's helpful!)
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