Some of you guys have experienced the screaming speedometer syndrome in cold weather. Mine also goes nuts, reading 70-80 mph while I'm going 45. I am going to have Toyota put in a new cable and avoid the headache. Meanwhile, I am using a GPS to tell my speed. Quite cool and very acurate.

 

Mine did that years ago but would drop to 0 when I was driving. Turned out to be a sensor. Can't remember which one though.

 

Speed Sensor on the Tranny. About $170 online. Mine has been acting up, but keeps curing itself.

 

Cebby, mine acted up for about 4 months and then gave out late one night. When it gave out, the trans would not shift out of 1st gear. I limp 5 miles to the nearest dealer. Could go no faster than 25mph.