Stuck in overdrive

Overdrive relay usually fixes the problem. With the engine idling quietly, press the OD switch on the shift lever. Do you hear a click? If not, it is probably the relay. Located behind the glove box, passenger side. toward the center console. Pick up a used one on Ebay ( about $10 bucks) and swap it out. Cured my problem right away. Be sure you change the correct relay because Volvo hides several back there. I would buy the spare, then match it with the one now installed. If not the relay, you will need a new solenoid in the transmission. About $200 installed.