Difference between a PNP switch and PNP sensor? [850][1994]... posted by Keith  on Monday, 5 March 2001, at 9:32 a.m.
 

                      Is a PNP Switch the same as a PNP sensor? And if not, which would cause a tranny to not go into O/D
                      when cold and cause the Arrow Light to flash on the dash? Thanks.

                      Keith,
                      What you are describing is what the Volvo tech manuals refer to as the "gear position sensor". Also
                      called a PNP switch by some, but don't know why! It is a part about the size of your fist that is attached
                      to your gear selector by a cable. When you move the selector into gear, the sensor moves with it, at the
                      same time sending a signal (hence sensor) to the ECM. The ECM now knows what gear you want and
                      the TCM now controls the transmission. I am curious where the "PNP" came from...anyone?

                      --
                      Tony G, '94 850GLT, "82 240DL (mint) July '99 "Rolling" cover

                      The Parts fitche lists it as a PNP switch.
                      --
                      Rich K.

                      with a 1994 850, you can read the codes in the A1 diagnostic socket, and then let us know what codes
                      you have, then we could better guess at what is causing the problems you discribe. If you don't know
                      how to read and clear the codes there is a post at the link below that will walk you through it.

                      --
                      Rich K.

... posted by James Russell  on Tuesday, 6 March 2001, at 7:54 a.m. ...in response to "Difference between a PNP witch and PNP sensor?" posted by Keith.
 

         I had the same problem on my '96 854 -- arrow flashing on the dash. Dealer replaced the PNP switch
         and sensor -- under warranty thankfully. Good luck. Check the fault codes, but this is almost certainly
         the problem.

         James Russell          '96 854          '93 945T          '85 245 DL

                     TO all:

                     My volvo recently has been acting strange and I would like some opinions before I see the dealer.
                     Recently my orange arrow has been blinking (indicating a malfunction with my automatic transmission).
                     When the arrow is blinking my car is underpowered and barely moves until I reset the light using a
                     method of turning the car on and off. In the past I have only had to reset it once in a blue moon. Lately
                     this problem has been happenning often, especially after long trips--the next day when I start it the light
                     is flashing and the car is not working properly, I restart it and it is perfectly fine.
                     And Ideas???????
                     Ryan

... posted by Ray Niblett  on Wednesday, 7 March 2001, at 1:22 p.m. ...in response to "orange arrow and transmission" posted by Ryan LaBranche.
 

                     Probably the gear selecter switch. Also called the
                     PNP switch. Search for PNP on this board to get the
                     scoop. It is a fairly common problem. To be sure, you
                     would have to read the diagnostic codes. Have a look
                     at http://volvospeed.com/bay13.htm for instructions on
                     pulling the erro codes and step-by-step instructions to
                     replace the PNP switch (should you be so inclined).

                     The loss of power is because the transmission locks
                     itself into 3rd gear when an error is detected and
                     it is hard to start in 3rd. This is called "limp home
                     mode". Sometimes you can turn off the engine and
                     restart to clear it from the limp-home mode (sounds like
                     that is what happened).

                     One odd thing, most people report this when the air temp is
                     cold and the engine is cold.

                     --
                     Ray Niblett 95 855 GLT / 98 S70 T5M

... posted by Keith  on Friday, 9 March 2001, at 7:45 a.m. ...in response to "orange arrow and transmission" posted by Ryan LaBranche.
 

                     Yep..PNP. I have the same problem, same symptoms on my 94 turbo 850. It's an 80-90 dollar part,
                     Volvo charges around 370 to do it, a regular Volvo mechanic outside the dealership will cost you
                     around 250 parts and labor.