OBD (On Board Diagnostics) - FAQ

What is OBD?
OBD stands for On Board Diagnostics, the electronic self diagnostic system of the control units of a vehicle. Learn more about OBD in the OBD-Wiki. In our on-board diagnostics store you will find high quality diagnostic tools for your vehicles.

VAG-COM or VCDS® diagnostic software? What are the differences?
The diagnostic software VAG-COM has been renamed by the manufacturer Ross-Tech to Vag-Com Diagnostic System (VCDS®) several years ago.
Because of this, offers of 'VAG-COM' indicate that somebody wants to sell you an outdated software without support.
We are the manufacturer of the OBD-2 Software KOBD2Check, CAN-Sniffer Software KCANMonitor, the RKS+CAN CAN-Bus Interface, KPower and KDataScope. KPower and KDataScope are included in our car-diagnostics products exclusive.
We are official distributor for VCDS and CGSULIT OBD-scanner.

Physical access to the control units with VCDS...

is done via the OBD2 plug of the car or Stecker or the 2x2 plug for older vehicles.
The OBD2 plug in the car is independent of the generic diagnostic protocol 'OBD2'. The OBD2 plug defines only form factor and pin assignment of the plug.
The generic diagnostic protocol OBD2 is a small subset of the manufacturers diagnostic functions. OBD2 as protocol is intended only for emmission relevant functions.
Your car does not need to support the OBD2 diagnostic protocol, VAG uses KWP1281, KWP2000 or UDS/ODX. It is similar with BMW.

Is the generic OBD2 (EOBD) protocol supported by VCDS or KOBD2Check? Can I do the exhaust gas service with it?

Yes. With OBD2 (EOBD is the european counterpart of OBD2) nearly all post 2001 (petrol) and post 2003 (diesel) engine control units can be accessed.
From model year 2008, all passenger cars and from 2017 all motorcycles use CAN für OBD2 and can be diagnosed with KOBD2Check.
In many countries and modern cars the exhaust gas service is done using the OBD2 protocol and the engine control unit, e.g. with the exhaust gas service in Switzerland.
E.g. a VCDS HEX-V2 diagnostic system or OBD-2 software KOBD2Check plus CAN-interface with 'dongle functionality' is needed.

What are the differences between generic OBD2 and the manufacturer specific OBD (VAG-vehicles)?

Generic OBD2 works with all OBD2 capable vehicles. Emission relevant informationen and setups can be done (engine control unit).
The manufacturer specific (Audi, Cupra, Seat, VW, Skoda) OBD protocol can do much more: all control units in the vehicle can be accessed. Example: check ABS sensors, activate cruise control, key matching, configuration of the comfort system or checking injection timing of TDI engines.

What does KKL support mean?

KKL is an abbreviation for K1, K2 and L-line. These are 2 physical pins in the OBD2 plug, that can have 3 different functions: K1, K2 and L-line. These pins are used for the pysical signals of the diagnostic protocol.
K1/L-line is a special mode, some older control units need to be activated on the L-line prior to communication over K-line.
K1/K2 mode is used by some Audis with many control units. Here the pin of the L-line is used as second K-line.

What is CAN bus support?

While nearly all VAG (Audi, Seat, Skoda, VW) vehicles before 2003 could be accessed via K1,K2 and L-line, newer cars like e.g. Golf 5 use the CAN bus (Controller Area Network) for diagnostic messages.
With Golf5, Seat Altea and all new models of the Volkswagen group all control units are only accessible via CAN.
Our professional VCDS diagnostic systems with CAN bus support are downwards compatible with K/L-lines for all older models.
The CAN support can also be used for OBD2 diagnostics for non-VAG vehicles.
All new models independent of the manufacturer use CAN for diagnostics because it has been set as standard.

Which cars use diagnostics via CAN-bus?

All models based on the Golf 5 plattform and the new Passat 3c: Model year 2004+ VW Golf, 2005+ VW Golf Plus, 2005+ VW Jetta, 2003+ VW Touran, 2004+ VW Caddy, 2005+ VW Passat, 2004+ Audi A3, Seat Altea, 2005+ Seat Toledo, 2005+ Seat Leon, 2004+ Skoda Octavia.
Model year 2003+ Audi A8 and A8L, 2005+ Audi A6, 2005+ Audi A4
... all new models.

What does 'dongle-function' of the VCDS or RKS+CAN diagnostic hardware mean?

'Dongle-functionality' means that the software in connection with a 'dongle' diagnostic adapter is automatically activated from shareware version to full version. The software license of a 'dongle-adapter' resides in the diagnostic hardware itself. This means, you can install the diagnostic software on any computer you want and do not need to care about licensing. Plug your diagnostic cable to this computer and start working.
You need not type in any license keys.

Is it relevant where I buy VCDS? Isn't it all the same?

No. Depending on the distributor there are differences how much or few additional software is within the installation package or what kinds of support are available. We offer customer support via mail or the Dieselschrauber - community, via telephone or via remote access (live support) to your diagnostic computer.
KPower and KDataScope are only in our VCDS distribution inclusive!

Model coverage - which vehicles can I access with VCDS?

The HEX-V2 and HEX-NET interfaces support all Audi, Seat, Skoda and Volkswagen cars! Aditionally some other vehicles/machines with engines from VAG. Compatibility chart needless.
Additionally all other vehicles that are accessible via generic OBD2 with ISO9141-2, ISO14230 or ISO15765 (CAN).
Our domain name is 'dieselschrauber.org', of course our diagnostic systems work also on 'petrol cars', independent of the powertrain.

VCDS or OBD-2 Software KOBD2Check updates: Program- and manual updates, which costs occur and where do I get the updates?

Program mupdates for VCDS or the RKS+CAN system (KOBD2Check) are guaranteed free of costs for a duration of 2 years. We deliver the VCDS updates/ updates for our own software (KPower, KDataScope etc.) at the moment also at no costs for all older customers, but this limit has to be set because of legal reasons. If there are new features, of course your diagnostic hardware must be able to be used with them.
Manual updates are always free of charge.
You find the updates in your personal download area of your customer account in the shop.
Notification of new updates is done via the shop newsletter or directly via the integrated update functionality of the corresponding product.

Why are there lots of VCDS label files and what is their purpose?

The label files describe informations like measurement values, codings or adaption values of the individual control unit.
Our customer get regularly new installation packages / updates, integrated the the actual VCDS release that can be downloaded in the customer account.

Where do I get information about unknown control unit, i.e. a matching VCDS label file?

Mail us!

Can I do chiptuning with VCDS, can I read out maps etc.?

No. We provide diagnostic software, no OBD flash tools. You can check what a chiptuning does with your engine with our diagnostic tools, so they are a tool to check if a car has been chipped or not.
Our VCDS diagnostic hardware supports a special driver in order to use them with third party software that expect an ISO9141-2 compatible interface on a virtual serial port.

CAN I read CAN messages directly on the busses of the car?

No. VCDS uses CAN for diagnostics, but is no CAN development kit like the RKS+CAN. If you want to access directly powertrain CAN, comfort CAN etc., you will find help in the CAN-bus forum. We offer the matching official forum hardware, the CAN interface with software package (KCANMonitor, KOBD2Check).