Самая подробная информация marble fabricators тут.

Park brake not fully released – A fault is preventing the parking brake from being released.

Try to apply the parking brake and release it several times. If the problem persists, contact an authorized Volvo workshop. If you drive off with this error message showing, a warning signal sounds.

Parking brake not applied – A fault is preventing the parking brake from being applied.

Try to apply the parking brake and release it several times. If the problem persists, contact an authorized Volvo workshop. If you drive off with this error message showing, a warning signal sounds.

Parking brake Service required – A fault has occurred. Try to apply and release. Contact a Volvo workshop if the fault remains.

WARNING
If the vehicle must be parked before the fault has been corrected, always put the gear selector in P and turn the wheels so that they point away from the curb if the vehicle is pointing uphill or toward the curb if it is pointing downhill.