My '94 850 has been having probems occassionally over the past year that sound just like the description of the PNP switch problem that is described on Volvospeed and here on this board. Last time I brought it to a garage and told them I wanted the PNP swicth replaced, I picked up the car at the end of the day and they had replaced some vaccuum hoses and said they had "looked at the solenoid and it was fine". Of course the next morniing after being cold it was sticking and over-revving again (I shift down into 3rd until the car warms up).

Sometimes the up-arrow flashes when this happens but only about once a month, whereas the shifting problem happens whenever the car is very cold.

So today I brought it in to a reputable Volvo repair place and they ran the codes, came up with nothing stored as a tansmission error code even though the arrow was flashing 2 days ago! They say it should hav e stored the error. I will bring it back to them when the arrow is flashing. However they did find the following engine codes: 241, 214, 113, 232, 121, and 512 apparently some are fuel system, one is RPM sensor and one is low ECG flow.

Now is it possible the RPM sensor is causing the problem by making the transmission think the engine is running at different revs than it is? If so how is that related to the cold? Can anyone explain the other codes and how serious are they to be fixed (this car has > 220k miles on it so there are always little vaccuum leaks etc).

Arg. I just don't want to ruin my transmission driving in 3rd gear every morning!