Volvo Repair: Volvo 850 1995 20 V Winter Driving warning arrow, flash flash flash, proper diagnosis

Question
Hi Regis
The Winter Driving warning light flashes continuosly leaving the gear box in low gear! The only way I can get out of this situation is by turning the engine on and off for about 5 or 6 times then it will clear itself !
Any ideas?

Answer
THERE ARE MANY THINGS THAT CAN CAUSE THIS MOST COMMON WOULD BE A BAD NUETRAL SAFETY SWITCH WHICH IS ON TOP OF THE TRANSMISSION.IT WILL NED TO BE LOOKED AT FOR A PROPER DIAGNOSIS.THERE IS ALSO A SPECIAL TOOL NEEDED TO REPLACE THE SWITCH.BELOW IS HOW TO CHECK FOR CODES IN THE TRANS. CONTROL UNIT.IF YOU GET A 313 IT IS A BAD NUETRAL SAFETY SWITCH(AKA: PNP SWITCH)  

behind the passengers side head light are 2 small black boxes,1 marked A ,and 1 marked B.on box A there is a small wire insert the wire into the hole marked 1 then turn the ignition key to position 2 but not started.then on the box narked A push the small button for 1 second then release it.the small red light will flash a code back as a 3 digit number.there is a short pause between flashes for a single digit and long pause between the different numbers.example:
a 121 would look like this flash.....flash..flash....flash
write down each code,then after the first code repeats its self then press the button for 5 seconds the light will light when pressing button then go out when released,then the light will light steady again when it does press button fo 5 seconds again,this should have reset the check engine light.let me know the codes. i will tell what they refer to.
         Rege