My 98 Volvo S90's (73K miles) shift indicator jumped between W and E. I went to a repair shop and they
got 2 codes: P0705 and P0715. I was told that my PNP switch (or gear position sensor) has to be replaced.
I drived the car to my Volvo dealer and spent $98 for transmission checking. Then the dealer said that the
problem is not PNP switch or gear position sensor. The problem is the whole transmission. They got a code
311 and that meant (they told me) that the whole transmission has to be replaced (they said Volvo will
never rebuild the transmission). The cost for replacing transmission is around $4000. And after replacement,
they said, the computer system may need to be fixed, which may cost another $1500-2000. I looked up
internet and found that code 311 means lossing speed signal. Does code 311 really mean that I have to
replace the whole transmission? Please help. Thanks.

Seems a bit excessive to replace the box when the speed sensor - DTC P0715, Volvo code AT311 - and the PNP switch - DTC P0705, Volvo code AT313 - can both be replaced without removing the box from the car.

Find an auto transmission specialist and have them check it out. I was quoted £UK1000, many years ago, for a new box by a Volvo dealer but had two sensors replaced by a specialist for £UK95. That box was still going strong4years later when I sold the car.

Sure sounds like someone is trying to rip you off.