Suzuki dealer that can't diagnose it's own cars, quality.
Phone up some independent garages and ask them if it's supported on their diagnostic equipment, Thatcham Integrated Diagnostics supports it but it's expensive to keep up to date so lots of garages don't subscribe.
A lot of garages rely so heavily on diagnostics they can't be arsed to diagnose jack without it, in reality that car is so basic it should be easy to sort.