Cleaned NSS, car starts, but still throwing code

Hey all you jeepers out there....hoping someone can point me in the right direction. I ran into the NSS issue awhile back and I'm still fighting the darn thing. My car starts without any issues in park and neutral, but my reverse lights do not work and my check engine light is on with the p0705 code. I pulled the NSS, cleaned it per the various write-ups and reinstalled it. Still no lights, still have the darn code. I've been under my jeep multiple times trying to adjust it with no success. I've had it in reverse and moved the connection arm forward and back and the lights still won't light up. After talking with the local parts store guys, (who have been helpful in the past), they seem to suggest that it might just be a short in the harness or wiring.

I'm no electrical guru so I did some searching to see how to test that to see if it's the problem. I'd hate to drop $250 on a part only to find out that wasn't it. I've seen dozen's of articles on cleaning the NSS, but I can't seem to find anything about how to test to make sure the wiring and harness are good. (I've made the mistake before of assuming that looking good and working good are two separate things!)

Can anyone offer some troubleshooting advice?

What year?

Mine, 1987, was a bent pin in the bulk connector near the oil dip stick.

99. sorry, forgot to include that.

man, that would be awesome if that's what it was. I'll inspect again, though they all appeared fine.

Inspect wiring, inspect connector and all associated "pins" and if all is good, you are probably going to have to bite the bullet and try a different NSS.

Cleaning CAN but does not guarantee a return to function. It's electrical and they can go bad.

To try and save money, you could try buying a salvage yard unit, clean it and install it.

I looked at the connector, all the pins look good. I didn't have a lot of time since it was pouring rain out. I'm going to pull the whole thing off this weekend and re-look at all the wiring and connectors.

The one thing that doesn't add up is that the car starts perfectly, has no issue shifting into OD and gives me no issue other than the rev. lights not working and the code. If the unit was bad, wouldn't I be seeing other issues? Is there a way to check continuity before I start throwing parts at it?

I had the same issue with my 99. Same symptoms you're describing. It ended up being a broken ground wire under the passenger seat. I would suggest you go over all your wiring and check your grounds. I think there is another ground behind the drivers side tail light too.

Oh boy, this is going to be fun. Any possibility someone can direct me to where all the grounding points might be?

One other thing...I thought this was unrelated but with electrical I guess anything is possible. I just replaced my clock spring due to an airbag light, no horn, no cruise. Everything went fine...horn works, cruise works again, but I'm getting an intermittent airbag light. Comes on for a few minutes, goes off for a few minutes. doesn't matter whether I'm driving or just idling.

Alright, I checked both the ground under the drivers seat and in the tail light. Once other thing I forgot to mention. I have a drawtite hitch. There appears to be a white cord coming off one of the connectors that has a ground loop on it that is attached to nothing. I can't even see where it would go, it is seriously only 1/2 inch long white wire? WTF

Also, I am trying to test continuity in the NSS, but I can't find any diagram that shows what pins to test in each shifter position. I found this:


but my connector is on a 99 XJ and looks like this:



The pin locations don't match up. Anyone have a diagram for my connector? Please!!

UPDATE: I pulled the NSS again and cleaned it again. Tested continuity and everything checked out. No shorted wires or connector pins. I also pulled the rear tail light and checked all the wiring. Forget about my previous note concerning that white wire. i figured it out. Its there to ground the trailer wiring box, but it was spliced into the factory ground wire. All those connections look and test fine as well. NSS is readjusted and the jeep starts like a champ.

Still have the code and no rev. lights. One thing I did notice. The trailer wiring box is a little swollen. It it possible that the internal connections have corroded and are what is causing the problem? I really can't see how that would throw the p0705 code.

Any Ideas fellas? I could really use some input.

Have you checked for blown fuses with a test light?

not with a test light. I've pulled and inspected all of them. I'll double check them again with a tester. That wouldn't throw a code though, would it?

I'm taking my girl out for her birthday, so I'll have to check this tomorrow. I'll post up the results.

If the nss doesn't have power then no reverse lights and you will get the p0705

Digger87xj said:

If the nss doesn't have power then no reverse lights and you will get the p0705

Click to expand...

That is an idea, also sounds like the trailer wiring may be involved in the problem.

Specifically, check fuse #10, a 15a fuse behind the right kick panel. It powers the white wire in the NSS connector, pin #1. The connector usually has the terminal position numbers molded into it somewhere on the outside of the connector.

Using a test light with the clip connected to ground, check the fuse through the little test windows molded in the top of the fuse. With the key on you should have power on both sides of the fuse.

If not, it's blown.

If it is good. move out to the connector under the hood and test for power there.

Thanks Digger87xj!!!!

Success. Got my reverse lights back. disconnected battery to clear the code. We'll see what happens.

Turned out the fuse was actually missing. Honestly, I have no idea how. I've been trying to think back to when my rev. lights first stopped working. I remember checking all the fuses first and didn't realize it was missing because my owners manual says that position # 10 on the fuse panel is open. I think I have a gremlin in my jeep! LOL.

Thanks everyone for the help! Once again , comes through in a clinch!

eace: