Volvo Repair: Volvo Up Arrow and ABS light, vehicle speed sensor, flash flash flash

Question
Hello, Just yesterday our 1994 Volvo 960 wagon put on its "Up Arrow and ABS light" while driving.  The speedometer also is now not working.  The fluid levels are all correct.  The car takes off from a stop very sluggishly, I think it may be in some sort of high gear limp home mode.  I am an ASE certified mechanic, but have no scan tool for a Volvo.  I suspect the Vehicle Speed Sensor, but I can find no reference for it in my mitchell on-demand system.  If it sounds like the VSS, I could use some help locating it for testing and R+R, as all info I have found points to it being internal to the trans.  If it sounds like something else, please elaborate.  Thank you for your time, it is appreciated!

Answer
it does sound like a vss.it is located on the rear axle differential cover.the one on the trans compares engine speed to trans speed to see if it is slipping.the rear axle one controls speed signal to engine,ABS ,trans,and cruise control units and speedometer.it will be an analog signal out of the rear axle sensor.you can check codes manually


in the engine bay on the drivers side near the strut tower there  are 2 small black boxes one has  a wire attached to it.place the wire in the terminal marked 2 on the box marked A .turn ignition key on (not started)press the small button for 1 second and the code will be displayed as a series of flashes.a red led displays the codes.the code will be three digits.small pause in between flashes for a single number long pause between flashes for the next number.example 121 will be flash.....flash..flash.....flash.repeat three times or until first code repeats itself.to erase the code after all codes have been checked hold the button for a good 5 seconds then release the light should light steady,then press for another 5seconds.this will erase the codes.  email me the codes and i will tell you what they are..

#1 on box A is trans. socket