In order to connect your scaltool to the car, you need to locate the OBD connector. Usually, the connector is located in front of the driver, most often under the dashboard.

Some connector location examples

Toyota Urban Cruiser (2012):

…under the dash. Gotto get down on your knees to get to it, and upside down under the dash to even see it.

Opel Corsa B (1979):

…on the left side in the fusebox. Great place, very accessible, good example for other manufacturers!

Our Suzuki Wagon R+ (2002):
Under the dash, carefully hidden and made thoroughly unaccessible. Room for lots of improvement…

My 1979 Cittrun Acad:

Nope, no networks, no modules, no (original) electronics…no worries!

Scanning for codes

On our Toyota RAV4 (2015):
The connector is located in the same place as the Urban. Albeit slightly better visible.
For fun, a quick code scan:

…which of course comes up empty. It’s a Toyota!

Obviously, the same goes for Urban; no codes!

The Opel Corsa B:
With this car, my scanner offers no less than 6 protocols for communicating with the car. Unfortunately, none seem to work. Most likely, a dedicated Opel scanner is required for this. Obviously, the car is an early example sporting OBD. Notably, Mercedes and BMW cars produced around that time still had proprietary connectors and protocols.