MostlyHarmless

So quick little background. My buddy has a 99 Cherokee 4.0 auto, and his deadline for emissions testing is coming up. His CEL has been on for a while, so a month or so back I scanned it, and among the 3 or so codes he had present was P0705. I cleared the codes, and a few days later the only one to come back was P0705. Did some research, and found it's most likely the NSS. I took it apart to clean it like everybody recommends, only problem was that half the contacts were completely corroded away, so there was nothing to restore. Put it back together, cleared the code again, and he drove around for a couple of weeks until he could buy a new switch. P0705 was the only code to come back during that time, as expected.

Anyways, fast forward a bit, and we install the new switch. When I first adjusted it, I used the reverse lights as my guide, and called it a day. CEL came back, P0705 again. Today I used the FSM instructions on testing the switch in each gear, and it turns out I had it slightly off. So I adjusted it, tested it in each gear, we made sure he can start in P and N, and the reverse lights work. I even checked for conflicting signals, i.e., that it wasn't reading N in Drive or anything silly like that. Cleared the codes, and he went home. Called me tonight, says the CEL is back on.

Now I'm stumped. I also checked for corrosion in the harness connector, everything seems fine there. I've Googled, and pretty much everything I find says P0705 is the NSS, and to clean/replace it, and that solves the problem. Anybody know of anything else that might cause this? Because if I scan this again and see P0705, I'm going to very confused.

Willys55

You will need to pull out a wiring diagram for the NSS. You could have an open circuit between to NSS and the PCM

SpyderJeep

I know very odd to have that effect the Transmission but it happened to me tonight.
SO I had a side marker/blinker that blinked but didn't light up as a side marker in my 1999 XJ Sport.
So I bought a bulb, not knowing what number to get the auto store person looked it up to be a 194. when I went out to replace it the bulb in the socket was a 168 so I exchanged the bulb for the 168.
I put the one in (right side, the vertical one) and drove off, within a mile the tranny shifts from OD to 3rd and back like I'm cruising just between to two and it can't make up it's mind... then I get a check engine light.
Fortunately I have a Bluetooth OBD2 reader plugged in and the Torque App on my phone to read the code right away. It is the P0705 code. I stop to clear it and it comes back even before I turn the engine over. I do this a few times to make sure it is not a false positive, no luck! I get home and Google "P0705 jeep" and I end up here as I have many times before. One thing stood out was the blinker bulbs. I changed out the other side to balance the ohms.. no luck!
I went to the auto store again to get the 194 bulb and see if it is the culprit...
Bada Bing Bada Boom!!! NO CODE!!!

I love how we can share our hard knocks here, I hope this helps many more!!!!