sprdav

Hello all. I have a problem I haven't been able to figure out. I bought my 98 XJ with a bad engine. After replacing the engine I keep getting these 3 codes (P0443, P0700 & P0705). It runs great but wouldn't shift into OD. First I removed the NSS and cleaning it. I cleared the codes, drove it again but that didn't fix the problem. Then I put a new NSS on, cleared the codes and drove it. Now it shifts into overdrive the first time I drive it after clearing the codes. I can drive it 2 miles or 100 miles and it shifts perfectly but as soon as I turn the jeep off and go to restart it, the codes are back. I then changed the Canister Purge Valve (code P0443), cleared the codes and drove it. Like before the jeep ran and shifted great until I cut it off and restarted it. Every time I restart it, the Check Engine light is on with the same 3 codes. If I clear the codes, the jeep shifts normally. Can anyone help me with this before I have to take it to the dealer? Thanks for your input

cpefy3

The codes you are describing are located in the TCU and as such are not "clear able" with most OBD scan tools. Either grab another TCU from the junkyard, or wait it out. Eventually the codes should erase themselves after the problem is solved for a certain number of on/off cycles. However, just turning the jeep on and off a lot will not duplicate the cycles needed. Hope this helps, even though it's an older post.

jasper_741

Hello not sure if this will reach you since the post is so old. But I was wondering if you ever figured out the problem? Your post fit my problem I'm having exactly. Please let me know. Im running out of ideas and money. Lol. Thank you.

agreen

I did a 5 speed swap on my automatic XJ. I couldn't get the 0700 and 0705 to go away after the swap. I had the clutch switch wired to the wire for park, and the reverse switch on the transmission wired up to the reverse wire. Turns out if the TCM doesn't sense the range sensor (which is pretty finicky) it'll give you a 0705. The P0700 is a generic TCM code it throws when you get ANY other transmission error code. It's likely that the TCM isn't seeing all of the range sensor. Side note, are you also getting the code for the purge solenoid too?

jasper_741

Yes I am. I even changed transmissions already thinking it was that but still acts the same. I changed out TCM 3 times now from junkyard jeeps. and still the same.. i thought about changing the NSS and the wire that goes to the shift solenoids but don't think it will help.. not sure why this is attached to your comment. 🤷‍♂️ Hopefully you get it. Im about to junk it but I've done tons of work to it and grown attached. Lol. Let me know if you have any other ideas.
IM in the process of finding a donor jeep and changing out the comp, steering column, tcm and wire to the trans. That way it thinks uts another jeep. Not sure if that will work. But it was mentioned somewhere else.

agreen

The shift solenoids aren't on the same circuit as the problem. But, neither is the evap purge solenoid. This leads me to believe it's a wiring or connection issue. Do the following in order.

1) Clean all your ground points. You have multiple issues that don't seem to be linked together by a single problem. I'd suspect either a ground connection is corroded or loose. There are many ground clean-up threads here and on naxja, and there are probably youtube videos by now. To REALLY clean up the ground connection points, get yourself a "piloted bonding brush". It'll attach to a drill and you can clean a perfect 1/2" spot in seconds. It's worth it.

2) Check the resistance values of the internal switches of the range sensor. There's one for P/N, R, D, 3, and 1-2. I'll post a diagram in a few.

3) Verify the range sensor is adjusted properly. Usually you do this by turning the key on, shift the trans into reverse, and have a friend watch the backup lights as you move the range sensor.

4) Check continuity of the wires going from the range sensor to the TCM. Also check that you have power and ground at the TCM. A factory service manual with wiring diagrams can be found at xjjeeps.com

509jeepguy

Did you ever figure out what the fix was? Im having the same issue but after shorting out a wire and blowing a fuse. Wandering If my problems is from a burnt up wire somewhere or if its really one of my codes. Jeep had zero issues till the short and it was just the sun visor light, popped my cluster fuse and nothing else. Instantly had a check engine light.

nicktread

I'm having a similar issue with my 98 XJ. I'm getting a P0700 and P0705. Everything seems to be running fine, but the codes keep reappearing when I try to clear them. Interesting to learn they are "not clearable" from the TCU.

cruiser54

Good place to start:CRUISER'S MOSTLY RENIX TIPS

TRANSMISSION CONNECTOR REFRESHING

OCTOBER 30, 2015 SALAD 22 COMMENTS



Over near the transmission dipstick tube are 2 rather large connectors. One is black and goes to the NSS and the gray connector goes to the transmission itself
. These 2 connectors carry all the info between TPS, TCU, NSS, speed sensor, and transmission solenoids.

Unplug each one, visually inspect for corrosion or bent pins, spray them out with electrical contact cleaner and plug them back in.

Additionally, if your Jeep is an ’87 to ’90 Renix, it’s always a good idea to reach up under the glovebox area and unplug the connector to the TCU and spray it out along with the receptacle of the TCU. While you’re there, find the fuse right in that area for the TCU. Remove it and spray out it’s receptacle and clean any corrosion from the fuse.