So I bought a '96 Jeep Cherokee Sport for my daughter recently. Right off the lot it threw a p1899 code. Also noticed the backup lights didn't work, which of course makes sense. We took it back to the indie dealer for repair. Now after the "repair" the back up lights work, but the code is still thrown. How could that be, and how can I get to the switch to verify the repair?

Thanks!

Chuck

Having this same issue but this post is from years ago, hoping someone has an answer.

Do your backup lights work? Can you start in park and neutral? What year is yours?

May only need adjusting. Perhaps removal and cleaning if you can get it off in one piece. Replacement if you can't.

TONS of YT vids online.

I'm going to guess that OP figured it out around 13 years ago.

For APAR, have a look at Bleepin Jeep's videos on the NSS.
https://bleepinjeep.com/video/how-to...safety-switch/

The best idea (imo) is to carefully remove the NSS, take it apart, and clean as per Youtube

Note; certain precautions should be taken

1) Degrease, clean and inspect the area first. It may be bad wiring

2) Mark its relative position

3) soak the shaft with penetrant, and in my case it required some fine wet & dry to polish the selector shaft would slide over it

4) Dont pry behind to get it out, its 30yr old plastic!

5) clean up with wet & dry & steel wool..you will notice a BIG visual difference

A replacement swithch is quite expensive, and who knows the quality.

As you will still have to remove the old one, you lose nothing by attempting to make to OEM item functional

(All the cooper contacts inside the switch will be covered with green copper sulphate, most devices with copper suffer this and can similarly be made good)

UPDATE: Thanks all for your suggestions! I was having this issue AFTER replacing my NSS with a new one. This is my first Jeep, owned it for just over a month now and it's a 2000 Cherokee Sport with only 80k miles (unfortunately rusty due to salt exposure and sitting for over 3 years).

For anyone else who ends up having this issue: Was getting code P1899 and P0705, replaced the NSS and reverse lights worked just fine, but the vehicle was starting in ANY gear. Found a "bypass" in the engine fuse box at the starter relay. Basically it was a grounded wire going to the starter relay wires. Previous owner must've used this as a work around instead of replacing the NSS. Removed this ground cable and cleared my check engine light with a scanner tool. Jeep has been running perfectly fine with no CEL for the last 100 miles and now only starts in Park or Neutral.

Its a good idea to take apart and clean that OEM NSS and store it away. It will be as good as new

To anyone that has a dodgy NSS (No crank), you should crank while moving lever between Park and Neutral. If it suddenly cranks, that is a warning that remove and clean out should be done.

(Not some bodgy workaround that causes the next owner to tear their hair out)

After cleaning up the NSS, add a little silicon dielectric grease (aka bulb grease) to prevent future corrosion and make it work a little smoother. For adjusting the NSS, put vehicle in reverse (engine off, parking brake on please), rotate back and forth and center it between where the backup lites go on/off. Snug the small side bolt before you snug up the big center bolt to prevent it from binding up.