Just bought this car and the up arrow comes on at random causing a rough idle and it sometimes dies at stop lights. Any help would be greatly appreciated. Great car otherwise, almost like new.

 

this is an automatic?

the yellow uparrow light is simply an indicator that the overdrive 4th gear is disabled when the light is lit.

the circuit goes from the button on the shifter to a OD relay to the light to the overdrive control solenoid. if the light is flickering,there's likely a bad connection or intermittent short somewhere in the circuit.

the OD solenoid should do nothing unless you're cruising over about 40MPH with light throttle or at some higher speed with more throttle. above those speeds, if the OD light is OFF, then the transmission will shift automatically into OD, and if you give it more gas it will shift out of OD, or if you push the button to light the arrow it will shift out of OD.

 

Thank you Pierce,

I know how it's supposed to work... I have the same thing on my Ford F250 and I can turn it on or off at will. The problem with the Volvo is that it comes on at random when no one is pushing the button on the shifter. When it does come on the engine runs ragged and stalls out. Pushing the button won't turn it off, but leave it alone for a while and it turns off by itself - I'm just driving around town and never over 40 mph when it happens. I'm suspecting the solenoid, but like everyone else, I don't want to mortage my house to pay the Volvo mechanic. Can I read the codes without hooking it up to a computer?

 

if its 'running ragged and stalls out', then you have a completely different problem, I'd be inclined to suspect a ground or connection problem behind your dashboard or something, and the OD light blinking is only a side effect.

on a properly working 240/740/940/etc, flipping the OD switch on/off should have absolutely ZERO effect on idle, only if its going fast enough to shift into OD would the engine RPMs go up/down as it goes 3rd/4th/3rd/4th...

 

I don't know if it would make the engine run "ragged" but many times the wire that runs connects the OD relay to the solenoid on the transmission will get frayed and may short out against the transmission. Crawl under the car and check the wire going to the solenoid on the transmission. If it is bare, tape it up to make sure it doesn't short out. See if this helps.

Good luck.

 

You're a Volvo genius! That was it. Replaced the solenoid and everything works right. The ragged idle was just dirty fuel injectors - unrelated like you said. A bottle of injector cleaner and it's all better. Thank you again.

Alan