SHORTLY: Be careful not to flush off the reverse position switch when you drain oil by the means of unpluging reverse position sensor down on the tranny, or you will loose your back up lights!

STORY:
Probably you guys know about it, however when I ran into this problem noone on org had a clue and only one !!!! person at all replied to my thread. When I was fixing my clutch 2 weeks ago and drained oil from tranny by unplugging reverse position sensor, the reverse position switch got flushed off obviously. I lost my back up lights and had no clue why. Checked fuses, leds and wires, then sensor for resistance and it behaved suspiciously, so I got new one at Nissan dealer. Together with it I got the switch, use for which I did not know and tech guy at Nissan dealer had no clue either!! After researching on Internet and asking people around I figured it gotta go behind the sensor, so I drained oil again today, unplugged the sensor, looked inside and yes, there it goes! Back up lights work again!

This is how it looks like:

 

So where does that piece go in relation to the black plastic plug?

 

It sits right behind the plug on a metal rod which moves when you shift. Hence switch moves as well and touches sensor's contacts in different way, letting it know the position of shifter and when it is in reverse and when not.

 

Excellent post. Thanks Vlad!

 

Very informative.
Thanks for the post and the warning.

 

I don't like pulling that sensor to drain the oil. I actually cracked the housing when I gently pryed it loose. Guess there is more that can go wrong as well...

 

Let's give it one more spin!

 

I don't get it, why would one drain manual tranny oil "by the means of unpluging reverse position sensor down on the tranny" in the first place? I changed my manual tranny oil with no such maneuver.

 

The drain bolt in manual trannies can be accessed only with a flat wrench, which sometimes does not provide enough grip and bolt gets rounded. For that reason it is a common practice to drain oil by unplugging reverse position sensor instead.

 

hmm, nice... I never knew that. Actually I didn't really need to know that, but thanks anyway.

I guess this doesn't apply because the big drain bolt on my max is perfect and I am able to unscrew it no problem each and every time. Although I will admit that unscrewing the sucker calls for an exceedingly precise wrench, which I have

 

of course be careful and don't do what i did and snap the bolt on the little black thing. Now my car sits on a jackstand trying to figure out a way to get it out.

 

hmmm....I changed my tranny fluid on my car last fall. I think I used a 1/2" ratchet to turn the bolt.

 

oops...that's for filling the tranny. The drain bolt i just used an open end wrench