The transmission overdrive relay often fails, preventing the transmission from shifting into overdrive. In some cases the Overdrive light may stay all the time or not come on at all. The relay is located behind the center console, just left of the glove box. Before replacing the relay it is crucial that the wire leading to the overdrive solenoid is inspected to ensure it isn't shorting out on the transmission case. Failure to check this may lead to a failure of a newly installed relay.Google+
Car Problem Reports
Volvo 240 Transmission Overdrive Inoperative, Upshift Arrow On All the Time
Volvo 240 Problem
Average Mileage: 144,902 mi (26,700 mi - 250,000 mi)
Visitor, 1992 Volvo 240, 26,700 mi
Light stays on wll not shift into overdrive.
Visitor, 1993 Volvo 240
upshift arrow on all the time
Won't shift into overdrive/sometimes will,sometimes won't.
Visitor, 1993 Volvo 240, 109,000 mi
Red overdrive indicator on, will not shift into overdrive. Not resolved
Visitor, 1993 Volvo 240, 199,694 mi
1993 Station wagon's Rear window would fog up and the Up shift arrow remained on. These two components have a common fuse. The fuse was replaced, problem solved.
Visitor, 1991 Volvo 240, 131,022 mi
overdrive isn't working have not fixed it yet. just got the car