DNNDRTY

Hey CF,

I've been looking through multiple threads on these CEL codes and still no luck for a remedy so here we go. I have a 1997 Jeep Cherokee Sport that originally threw a single CEL code of P0339 for a crankshaft position sensor, but experienced no symptoms of bad sensor. After replacing the sensor myself the CEL error went away only to come back a year later. Thus, I decided to take the jeep into the dealership to let them look over it. The dealership said nothing was wrong with the CPS, and that according to a TSB, my PCM needed a flash to resolve issue. So the dealer charges me for a flash of PCM and the CPS code (P0339) goes away. Two days later (weekend) my CEL comes back on and this time throws 4 codes (P1694 - Bus Communication Error to PCM, P0705 - Transmission Range Sensor Circuit Failure, P1899 - Neutral Safety Switch, and P0700 - TCS Malfunction). I immediately take the jeep back to dealer and ask that they confirm this is not related to the PCM flash they performed the previous week. Keep in mind my jeep was showing no symptoms for the any codes so far. The Jeep dealer told me they cleared the codes and the issue was a strange coincidence and that my Neutral Safety Switch (NSS) needed to be replaced. Before wasting any more money with the dealer, I brought the jeep home to troubleshoot myself. I started by cleaning my NSS and 3 CEL codes eventually returned (P0700, P0705, P1899). So I caved in and bought a new mopar NSS and installed it. It has been months since installing the new NSS and without showing any symptoms the codes have re-appeared frequently. I have been clearing the following codes with an OBD each time:

Codes Dates Triggered
P0700 - 7/22, 7/28, 8/12, 8/29, 10/4, 10/14, 10/16
P0705 - 7/22, 7/28, 8/12, 8/29, 10/4, 10/14, 10/16
P1899 - 7/28, 8/12, 8/29, 10/14, 10/16

So I have not seen CEL Code P1694 or P0339 since dealer. And the CEL codes P0700, P0705 and P1899 have been firing before and after NSS cleaning and replacement.. Is it possible the NSS is still the issue? My transmission fluid looks and smells good and its at the right level. I looked over wiring and plugs and they all look good. The NSS looks good and i have no symptoms of a bad one (my shifting is good, the jeep responds well, no brake/reverse light issues). If anyone has any recommendations or had similar issues please let me know. Trying to avoid dealer At this point the jeep runs and I clear code when CEL annoys me, but I would love to resolve any ghost gremlins causing issue.

I'll continue to review other threads on these codes in the meantime.

Cheers!

Idunno

Phantoms. I keep getting 0740 (TCC lockout malfunction) but the trans locks out fine. This is on a 98 that I replaced the TCC solenoid valve and brake switch (in the circuit). If I keep getting that code it must be a wiring harness problem that trips the code but there's no other malfunction. I'm going to go harness diving to see if I can trace the problem when it gets a little cooler (central Florida).

DNNDRTY

Think I might replace TCM this weekend. Any other recommendations of that fails to resolve?

awg

So a code is thrown if the sensor or its wiring is faulty
Is possible a common wire that supplies power or earth to those circuits is defective, causing an open or short circuit, which will set a code

a study of the wiring diagram from the FSM would be useful bed-time reading

probably worth cleaning the TCM main connector

DNNDRTY

Thanks for the feedback. For fun I unplugged the TCM and then plugged it back in and the CEL has not returned since. Been a few weeks so if it comes back I will look into a faulty TCM or wiring

fb97xj1

Might have been a dirty cavity, or pin, and was cleaned a little by disconnecting it, and plugging it back in. Hopfeully that was it. But if not, The TCM (if thats the issue) was a one year deal for 97. Doublecheck the grounds near the airbox. There are two identical grounds on the inner fender The NSS (Range Sensor) uses one of them. Mine were pretty dirty and the inner fender was dimpled a bit so the connection wasnt the best to begin with. The ground screws are exposed to the elements on the backside, so they get wet easily. Mine were a little rusty. The TCM itself uses a ground by the ignition coil. Check that one, too.

Credit to CCken for the pics.

97grand4.0

One. NEVER go to the dealer unless you're 100% under warranty. Even then, never go there.
Two., P0700 and 0705 are TRANSMISSION codes.

DNNDRTY

Thanks, CEL came back after new TCM. I am cleaning grounds now

97grand4.0

OK.
Cleaning grounds, while a satisfying general maintenance exercise, and hoping to clear 3 codes, is like taking a cod liver oil pill for a cold and hoping it cures it.

It might help, a little.

Changing out the TCM, when you have a malfunctioning transmission that's throwing 3 codes, is like shooting the messenger when you don't like the message, or firing the well used parts cannon. You kill the messenger but the next one brings the same message.

Here we have 3 codes. P0700 says there is some problem with the transmission. Not specific but a leading indicator, so..
P0705..is more specific. Transmission range sensor circuit malfunction. This means that somehow the transmission is not seeing what gear you have shifter into. It also means there might be something called a range sensor that is not working right.
Finally we have the P1899 code. This clearly says something is wrong with the Park/ Neutral switch, formerly known as the NSS or neutral safety switch. So we see a pattern here. Now, if either the Park N switch, or the range sensor, depends on the other to work, then all 3 codes could be just one of these 2 malfunctioning.
Pick the easiest to fool with and start there, my guess is the PN switch.

TeXJ

So it seems that the 97 year model is notorious for the p0700 code. That code is a generic code for the transmission. I've been working on solving my issue for over 5-6 years. Just search for p0700 cherokee and you'll more than likely see my post in that post.

Mine would only come on when I'm off roading. I would clear the code and then it wouldn't come back on till I went off roading again. The last few times though it has come on and stayed on even after clearing the code.

I took it to a tranny shop and asked if they have the code reader to actually read the chrysler code for the tranny. They couldn't find an issue with it and thought it might be electrical, something with the tranny wiring harness.

I had a good buddy with me that's a long time jeeper, he broke an axle in his jeep so he rode with me the rest of the trip. Sure enough the light came on, he mentioned that it could be from the tranny getting too hot. Being OBD2 and still new for the manufacturers, they may not have an actual code for "hot". So the generic p0700 code would come up. Kind of like a place holder.

Now the AW4 in the 1997 cherokee is a bit of a bastard. It has wiring from a 96 but the connectors of the newer model years. It was also the first year of the revamp of the cherokee for 1997.

Right now I ordered an external tranny cooler and will try this to see if if solves my issue. My tranny also shifts fine and doesn't seem to have any torque converter issues.

TeXJ

also, where is the TCM and the tranny wiring?

fb97xj1

The TCM for 97-01 is under the dash, by your right leg. The 98-01 arent that bad, but for 97, the top bolt is a real PITA as its hard to see. Last time i took mine out, i took my Dremel and cut a notch in the TCM so i could just loosen the bolt and unhook the TCM from it. The TCM wiring snakes up into the dash and over the steering column. It eventually passes thru thru the firewall and is bundled with the main harness..

TeXJ

Thank you!

I'll be able to take a look and see what I can find. Thank you!

DNNDRTY

Sorry I have been absent. I am now investigating a completely separate CEL for P0303. Once I resolve that I will jump back on this roller-coaster. I have cleaned my grounds with no luck and my torque converter might be putting off a really bad whine (like and old van in reverse lol). Not sure if a bad torque converter could be causing these transmission codes?

DNNDRTY

Okay finally time for some updates. I had to address a misfire issue and the resulting CELs with that. Turned out to be a bad fuel pump and needing new spark plugs. While troubleshooting the fuel pump and replacing I found a bunch of pin sockets in my fuse box had fallen and where not making contact with my relay/fuse pins. I fixed this and have not had any CELs for a while now. With that said I have also being keeping the jeep to local short drives because I believe the Torque Converter is going bad. Going to address that in the coming weeks. If I get any more ghost CEL before or after fixing that I will you all know.

Thanks