hi..sorry to open another thread in less than 3 days regarding the same issue...however,
I will change my 6-speed trans oil in Fri....and I have a SES of P1706 which is ;

Neutral position switch

my reverse lights don't work when I put the shifter to reverse (I put new bulbs , checked fuses and all working)
Now I know that to change the sensor, I have to loose the old trans oil (it will come out) so I want to do both jobs toghther ...

My question should I change the Neutral switch (as SES indicates) or the Reverse switch , to make my reverse lights work again when I back up ?
thanks

 

The neutral switch does not used in any way in the backup light circuit.

 

I think the two share the same harness.

 

so that harness will come with one of the 2 switches , can be fixed or must be changed ?

 

The wire harness would not come with the switch. It is curious that you have problems with both switches at the same time. A damaged wire harness going to the transmission could be the problem, but you need to do some testing to find the exact cause. Using the "shotgun" method of replacing all the parts (switches, harness) would most likey fix your problems, but you will throw away money replacing good parts.