hi, i have a 92 Volvo 960 with 198k miles and the arrow on the dash stays solid. the mode switch will not change from w,and there are no lights flashing.(and no codes from ecm)
it seems to run very well on the highway but in city it has poor take off from
standing stop. can any one give any advice on where to start?(relays,switches...ect)

 

Not 100% where to start but your car is likely starting off in 2nd gear. I would start the car and switch back and forth from E to S about 20 times to see if that gets it out of the W mode. W is for Winter.

 

The button controls if working correctly are supposed to go as this, w mode button never stays down, it is activated by pushing, but the button itself stays up. This is so when the engine is turned off, the buttons reset to the E or S button that stays depressed.

If you turn off the engine and the trans is still in W mode, then you might be having trouble with your PNP switch, the computer is not able to read what gear is selected. So the default is to start out in 3 gear, not too good for the trans at repeated start outs. Again that is why the W button works the way it does, to prevent trans from overheating.

Try this and see what happens. Ignition on, engine off, foot firmly on the brake pedal, move gear selector 30-40 times thru the gear range of park and L. Place in park and start car, does that change anything?

If so, your PNP switch which mounted on the trans is failing, and soon you will not be able to even start the engine as it will not be able to sense the park position.

The PNP switch gets it's lubricant cooked because it is next to the exhaust down pipe on the side of the trans, after awhile, the cooked grease does not allow the small contact springs to work, this confuses the computer and causes start and running problems.

DanR '94 964 356,000 miles (122,000 on the new engine)

 

mine has done the same thing. It only sees to do it when there was a big temp. change. It came out of it after the temp. warmed up. Perhaps put the car in the garage and turn a heater on and see if that helps? Good luck

 

I agree with the temp change statement. I live in Texas, and I never seem to have an issue with this in the summer. Soon as it starts to get cold, I have issues. Sounds to me like once the grease starts getting old (and cooked as Dan says), it just doesn't respond well to cold weather.
This also suggests that should you want to, theoretically you could remove the switch, open it up, clean it, re-grease it, and be back on your way. From what I read here and other places tho, this has mixed results.
I am personally just going to replace it, since you have to take it off anyway to clean it.

 

If both the W and E are flashing and your UP arrow on the dash is on, the PNP switch is the most likely cause.

Replacement is the cure.
Trying to repair or re-lube the switch usually does not work.

Tony L.
www.swedishautoparts.com

 

I replaced the PNP switch but there was no change ie. winter mode arrow
still solid and the "w" on the mode switch stays on!

Are there any relays involved in this mode change function?