I recently posted a message asking for help regarding flashing red arrow on dash indicating transmission problem. This occured when the temperature was below 30 degrees, and the computer was trying to put the system in winter mode. The lights by the gear postion stick would continually cycle between W,S and E. The car would start, but it started in second gear. If the engine was switched off, it would not start again until the computer reset, about 5 minutes.
I have a 1995 Volvo 960. Several other people had the same problem. A dealer couldn't fix it, neither could a local foreign car place.From a friend, I got the name of an independent foreign car mechanic in Toano, Va. who diagnosed the problem and repaired it.
He first checked out the failure code which was 313, which indicated failure of the PNP switch on the transmission (Volvo part #9466013) He replaced it and corrected the problem. He then cleared the trouble code, and all is well. To reset trouble code LED, switch on, engine mnot running,deprees button for 5 seconds and release. While the light is lit and displaying the old code, depress again for 5 seconds. When released, it will reset .
This also relates to the PNP switch AND the connectors for the switch, temp sensor and shifting solenoids on my 1995 960 with 127K miles:
Symptom story: I drive 30 miles to work, mostly I-4 in central Florida. I don't know much about the car's background. At speeds up to 60 mph, but mostly around 50 through downtown Orlando the car performed flawlessly. When I came off at the exit I had to stop for a light. Light changed and I took my foot off the brake and pressed on the accelerator - nothing. It was like I had put it into NEUTRAL. (Deduced later that that was, in fact, what had happened internally.) As cars began honking at me holding up at the green light, I placed the gear in park and shut off the engine in preparation to restart it. (Resetting Windows habit.) I was flustered and it took me over 10 seconds to finally turn the key. It started immediately. I put it in gear and the stupid thing drove as if nothing was wrong. No CEL (check engine light.) No warning lights. Nothing. This occurred at random intervals over the next 3 weeks, but then the CEL began to come on. I learned how to read the codes (thanks, guys, for all these forums and info) and I got a plethora of codes. No just two or three. A plethora. So many that I just read them; cleared them; cranked it up and drove until it happened again. I went to several mechanics with whom I have built up relationships with over the years. They all seemed to agree that the transmission needed rebuilding; $3000. I just didn't think so. It pulled too strong and when it worked - it worked great. About this time I was attacking the codes one-by-one and that led me to the PNP switch problem. I also noticed that I had no reverse lights. I went to a u-pull-it salvage yard and got a PNP switch for $25. I pulled it apart carefully (according to internet research.) I cleaned it. Stretched the contact springs, LIGHTLY. Re-greased with Sil-Glide; a high temp, silicon grease that I've been using since 1975. (It works great for keeping battery terminals from corroding again after cleaning.) I installed the switch and noticed that I still had no reverse lights although the trans problem seemed to have cleared up a "bit". (It didn't poop out as often.) I began a point-by-point clean-up campaign on all the ground points that had anything to do with engine or transmission...and there are a lot. This accidentally led me back to the left side of the transmission where the three connectors are located for the temp sensor, the PNP switch and the internal solenoids. While looking at the wiring harness connector (8 sockets) that plugged into the PNP switch connector (8 pins), I noticed one wire looked "funny" - and for good reason. It was no longer connected to the crimped on socket connector. I began tugging at these wires that went from the main wiring harness to the connector and several of them were not even connected any longer! I cut the remaining wires from the connector and examined the connector. It's a plastic box that has "ears" that fold down over the socket connector that is encased in a short plastic tube within the box. What was astonishing was that most of the sockets themselves had DISSOLVED. This left the wire to be just held against the inserted plug from the PNP connector. As it was driven the wires vibrated away and toward the connector sometimes making contact and sometimes not. I have been fortunate enough to be able to find replacement sockets at an equipment salvage store, a real good hand crimping tool (Crimper, Ratcheted, AWG 20-18, 16-14, 12-10, ..non-insulated, open barrel terminals $35 - Amazon), clear plastic water tubing (5/16" OD x 3/16" ID). I have literally rebuilt the connector block. Car starts and runs great even though this has been a 2 year process with it sitting a lot. I don't like cars that leave me on the side of the road AND I'm stubborn. I am now well versed in replacing ALL fluids (including brake) and doing flushes. Next - timing belt kit.
I had this problem with my 1993 960 wagon. I replaced the PNP switch with a used one,the program switch(the threebuttons near the shifter) with a used one and also the speedometer with a used one. The switches were from my parts cars and swapped a headlight with a friend for the speedometer. (1993 only) Total cost $00.00 20,000 KM later, all is still well.