Mary's car ('04 V70) wouldn't upshift from second or third, the speedo would only show 20 mph (the tach read ~5k so I'm sure she was keeping up with traffic...) and the ABS light was on. Rowing through the gearbox would make it behave somewhat as long as she did not put it back in Drive.

Cleaning the sensor 'gears' on the ends of the axles and the ends of the ABS sensors made it act normal again. There was a gob of ice on the end of the left sensor. I sprayed them both with a little silicone oil to try to keep the water at bay.

Greg

Also own a 2004 V70, no problems of the nature you have described but Worth having a clear understanding of it in case.....
-- You mention ice creating a problem for the sensor... Isn't it mounted
where brake pad backing plate heat would resolve it??? Dirt I can understand being an issue. I am not sure of how the sensor is actually mounted....not having had any problem so far.
You mention cleaning the "sensor gears' ???? can you clarify the term.
I havent been able to pull up a good picture of the area being discussed and I
am not going to go looking ..... we are in a New England winter this year!!
Thanks
Art

Art,

Your winter is mild compared to what we have been going through - waking up to -20F and having highs below zero is not condusive to ice melting. Greg lives on a farm, out in the boonies, so that there is very little braking action required during normal errand runs.

The 'gear' that was mentioned is the toothed sprocket on the axle, ABS ring, and the sensor picks up rotation from that. It is a magnetic pulse from the metal ring passing under the sensor that the ABS unit is looking for. Thick ice shouldn't have any effect, but the amount of salt used on the roads around here could have a bearing. BTW, road salt doesn't work in temps under 15F and 15F is considered a warm front this December!

Thanks Klaus, It is a big help to understand circumstances that could precipate
a problem like this (and hope it never occurs)and that the fix could be quite simple.
Your right about weather: The weather system they threatened NE with yesterday produced all of about 1.5" of snow (not even enough to make my wife's XC have to work a bit. My V70 spent the day sheltered in the garage.
Merry Christmas to you and all the helpful site members,

Art, Mystic, ct.

Poor Mary! It is a good thing you have a lift to easily check those things. The silicone should work.

Kind of makes me wonder if the skid control logic kept the car from changing gears, like there is one wheel slipping.

But why was there ice forming on the sensor? That should not happen, ever. It gets cold in northern Sweden too.

I'm glad that Mary is a resourceful as she is.

A lift makes everything easier, but as long as you get both front wheels off the ground at the same time it is very straight forward. The rotors can be turned with your bare (or gloved) hands. I used a screw driver to wiggle the sensor loose rather than just tugging on the wire.

I think what happened was that the brakes had gotten warm enough to bring the sensor above freezing and plowing through the drifts splashed enough snow in there to make a droplet on the end of the sensor. I should probably check to see if teh left caliper is sticking...

Greg