Baud rate Opel Meriva

Hello.
I used an oscilloscope to tap into the CAN bus on the instrument cluster of an Opel Meriva (CAN High wire color: green, CAN Low wire color: white). The signal is clearly visible. Does anyone know the baud rate of this bus on the instrument cluster? I want to log it using CacHack. I've already tried the common settings (125Kb/s, etc.).
Best regards,

Frank6 wrote:

Hello. I used an oscilloscope to tap into the CAN bus on the instrument cluster of an Opel Meriva (CAN High wire color: green, CAN Low wire color: white). The signal is clearly visible. Does anyone know the baud rate of this bus on the instrument cluster? I want to log it using CacHack. I've already tried the common settings (125Kb/s, etc.). Greetings

I'm not an Opel expert. Therefore, just the usual: Are you absolutely sure about the H and L?
Normally, you should be able to determine the baud rate by observing the shortest high or low phase within a message.

Best regards,
Ingo

Hello,
'Thank you for the response. I've attached some pictures of the CAN bus. When I measure the bit time, I'm actually getting a transmission rate of 50 kb/s. Is that correct? I'm using a self-built interface from the 'Kreative Chaos' website. However, I'm not receiving any data at 50 kb/s. I haven't swapped the low and high lines.' You can clearly see what's happening on the oscilloscope.
Regards,
Frank.


P.S. On a side note.
Which CAN debugger interface would you recommend that works well with can tool, supports non-standard baud rates, and isn't too expensive?

Hello.
All the pictures are attached again!
Regards,
Frank.

Hello,
50 kbit sounds like quite a low speed.
At Audi and VW, 100k is used in the comfort/infotainment area, and 500k is used in the powertrain area.
From my perspective, you should utilize the bit-stuffing mechanism of the CAN bus to determine the clock rate. The CAN bus specification defines that a maximum of 5 identical bits can be transmitted consecutively on the line. If an application wants to send more than 5 identical bits, so-called "stuff bits" are inserted. More about that will be explained to you by http://www.canhack.de/en/viewtopic.php?t=13.
That means for you, you need to find the longest block on the oscilloscope, divide the time span by five, and that will give you the clock frequency.
That would be my approach...

Greetings.
Jens.

Have you tried using these baud rates?


Title: Opel CAN Bus for Astra/Vectra/Signum.

500kbps pin6 CAN-H, pin14 CAN-L for engine control unit, TCM transmission, ABS/TC/ESP, electronic damping system, and power steering.
95.2 kbps on pin 3 for CAN-H, pin 11 for CAN-L, for all displays (TID/BID/GID), radio systems, CD player, and automatic climate control.
33.33 kbps single wire pin1 for AT6-ECU, Airbag, Instrument, ZM modules, PEPS=Passive Start, Tire Pressure Control Unit, Parking Assistant.]

I had success with that on the Zafira B.

Greetings.
slowmotion64