If you have volvo genuine navigation then you may use following steps to trigger the hidden diagnostics menu.
- Ignition to II and turn on the RTI-NAV (screen comes up out of dash and has safety warning showing)
- Ignition to 0 (display goes back into dash)
- Ignition to II – screen comes back up, but now shows RTI logo
- Press back – return – back on the steering wheel controls, while the RTI logo is still showing