CAN present even if no CAN on OBD?

'Am I understanding correctly that a CAN bus can be present in a car even if it's not accessible via the OBD port (e.g., through the OBD connector)? Would that only include comfort features?'

Hi Mike,

It's certainly possible, but it would be very unusual.

What kind of vehicle are we talking about? (ideally with the year of manufacture).

Regards,
Peer.

It was just a general question to understand something, as I've repeatedly read that people can tap into the CAN bus via the radio. I wondered why (and I'm still wondering now), because if the CAN bus is connected to the OBD port, shouldn't it be much easier to access there?

Hi Mike,

Sure, it's easier to tap into the OBD connector.

That's also a security question for me.

The CAN connection on the radio is a Comfort-CAN interface.
There are no motor-related data that can be tampered with.

The data I can receive via radio is sufficient for my personal needs.
(I still haven't found any online tuning options for my Stilo yet.)

If you're careful enough (regarding what you write to the CAN bus), you can easily access the engine CAN via the OBD port.

Regards,
Peer.

Okay, how? CAN is a bus system. So, it shouldn't matter where I tap into the data. The same information should be available everywhere. The only difference between diagnostic and comfort data is the speed at which they are transmitted. But if there's CAN on the OBD connector, I can access all that information there – the same goes for the radio.

As far as I can tell, my RX-8 also only has ONE CAN bus, specifically the engine CAN bus which is connected to the OBDII connector. However, this doesn't transmit comfort functions like button signals or radio display text.

My dealer told me that I don't have a Comfort Can at all; could that be possible?

'To the Dean: It's certainly possible, but it would be a bit unusual...'

@Mike: It's not that simple. If the speeds are different, then logically, the data won't be transmitted over the same bus!
Therefore = 2 different and hardware-separated bus systems!

Also normalerweise gibt es mehrere Busse im Fahrzeug, Komfort Bus,Motor( Antriebs) bus und den Sicherheitsbus (Airbag) alle Busse sind jeweils ein eigener Kreis in den verschieden Aufbauarten Sternbus, Ringbus, etc. Nun um überhaupt alle miteinander zu verbinden kommt das Gateway (Dolmetscher) zum Zug, dieses wandelt die unterschiedlichen Bitraten in die jeweils passenden für die verchiedensten Busse um und wertet auch die anderen Daten aus. Das Gateway sitzt üblicherweise im Kombiinstrument. Von dort geht auch die Diagnoseleitung zum OBD Stecker. Daher können Diagnosegeräte auch alle Busse lesen. Diese gehen über das Gateway zum lesen. NuAn external reader should be installed after the gateway (e.g., on the radio or air conditioning unit), and from there, it is possible to... If something is accidentally sent, it doesn't directly address the control unit on the drive or safety bus; instead, it's re-checked for correctness by the gateway, which may identify it as incorrect and prevent it from having any effect on a component. The gateway also converts different data rates. That's how it should work.

Ponder.

Of course, there is CAN without OBD. For example, Mercedes has been using it since 1888 with the introduction of the SL model (using a 'motor-CAN' system).

Mercedes was one of the first automotive companies to use CAN (Controller Area Network) technology.

Here's a brief overview of Volkswagen.

[Dead link]

Beispielsweise bei Mercedes seit 1888 mit Einfürhrung des SL's.
Interesting

Oops, it was the W129 of 1988, of course! *g*

Hi.
CAN YOU HELP ME?
What software is recommended for reading OBD2 fault codes on a Fiat Stilo using a CAN USB interface?
cPOS IS NOT WORKING.

Hello Tim,

The Stilo does not have OBD2 implemented on the CAN bus. Instead, OBD2 functionality is only available on the K-line connected to the engine control unit (ECU), which is pin 7 of the OBD connector and operates at a data rate of 10400 kbps using the KWP2000 protocol.
With your can tool interface, you can perform various monitoring and command-sending functions on both high-speed and low-speed CAN buses (provided you know the commands to send). However, OBD2 functionality can be achieved with a simpler interface like an ELM323/327.
Before using high-speed CAN, you'll need a solid understanding of the message structure.
All low-speed nodes (50 kbps) can be controlled using KWP2000 commands (a service reset is just one of the many possible commands).

Gert.