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Tranny won't shift into overdrive... TCM?

helliphinon8

NAXJA Forum User
Location
Queen Creek, AZ
I've searched all forums and found nothing. I have a '98 XJ Classic with 150,000mi and a 6in lift with 33's and stock .355 gears. The problem is that it sometimes won't shift into OD . It does shift into OD most of the time, but when it doesn't, the check engine light comes on. I went to vatozone and got the codes pulled. Two were transmission related. 1st was P0705, which states "transaxle range switch fault", speed registered and the ECM detected an incorrect input from the transaxle range sensor- probable cause- failed tranny range sensor. 2nd was P0700, which is transaxle control system fault- explanation- a signal from the transaxle control module has a fault. My ? is... has anyone else had this problem, and what's the fix? Is it just the TCM, or is it a problem stemming from bigger tires with stock gears? And if all is true.. how do I fix it? Thanks in advance. N8
 
Adjust, clean, or replace the Neutral Safety Switch NSS. Inspect the NSS connector for corrosion and the NSS wires for damage.

Possible causes
- Open or short park/neutral position (NSS) switch circuit
- Poor park/neutral position (NSS) switch circuit connection
- Mis-adjusted park/neutral position switch (NSS)
- Park/neutral position (NSS) switch may be faulty
 
Try unplugging the battery for 10 minutes to reset the TCM. I would replace the range sensor if the code persists - or at least check the wiring to be sure it is intact.

just my $.02

Good luck!
 
Another problem can be the brake pedal switch.
 
Shift points normal? when mine was doing that it turned out to be the TPS, but like i said, my shift points were a little higher than they used to be as well. NSS is located on the passenger side of the transmission. Look at the Go jeep website for a walk through on cleaning it. i broke two trying to get them off, kind of a PITA
 
Just had the exact same problem with mine man. Its prob the Torque Converter Clutch Solenoid. I had the same problem it wouldent shift into OD. Had a guy replace that and now she runs great again.
 
This is likely a Neutral Safety Switch issue. It is a pie-shaped piece on the passenger side of the tranny. Remove it, clean it, and reinstall it. It is very common to lose OD when the NSS is dirty. P0700 and P0705 are very often the NSS.
 
^^I agree. I had these codes when I purchased the 98 2 years ago. Took all of 45 minutes or so to remove, clean, reinstall and adjust. Losing the lockup is a very real possibility. Before jumping off the deep end and replacing solenoids, clean the NSS.

Unless it gets broken, there is no good reason to put in a new NSS so, do a search for the cleaning process, it is well documented here...
 
It could also be the Flux Capacitor or the Di-Lithium Crystals.

Since there is a Check Engine Light and a P0705 NSS fault code, the NSS is the logical place to start diagnostics and repairs.
 
Adjust, clean, or replace the Neutral Safety Switch NSS. Inspect the NSS connector for corrosion and the NSS wires for damage.

Possible causes
- Open or short park/neutral position (NSS) switch circuit
- Poor park/neutral position (NSS) switch circuit connection
- Mis-adjusted park/neutral position switch (NSS)
- Park/neutral position (NSS) switch may be faulty

NSS is bullsh!t. I got a new one from a friend at Chrysler. NOT THE PROBLEM! But thanks for leading me to believe that was the problem. It was an un-necessary pain in the ass. THX!!
 
So the NSS helped the reverse light problem, but nothing else. I actually drove the Jeep for 20 miles with it in the "mystery gear' between 3rd and 4th and it ended up pushing tranny fluid thru the dipstick tube and onto the exhaust. (keep in mind I have the extra towing tranny cooler too). Still, there's only 1 person that suggested another thing, jeepfreak1020 with the Torque Converter Clutch Solenoid idea. Is it my next step? Im almost ready to just sell this b!tch!! It's really starting to drive me nuts. It's my Daily driver. Fu*k japanese transmissions!!!! WTF was chrysler thinking????? Dumb bastards. :smsoap:
 
Sounds like you need to have a brew and spend a day on the interwebz, bro.

Start with some simple diagnostics, not parts throwing. You threw a NSS at it an it didn't work. I'd say verify the TCM is working correctly next.

I googled "no overdrive aw4" and COUNTLESS threads came up on the same topic. Many of which are from this forum. I'll let you take it from here...
 
Try unplugging the battery for 10 minutes to reset the TCM. I would replace the range sensor if the code persists - or at least check the wiring to be sure it is intact.

just my $.02

Good luck!

Another problem can be the brake pedal switch.

Shift points normal? when mine was doing that it turned out to be the TPS, but like i said, my shift points were a little higher than they used to be as well. NSS is located on the passenger side of the transmission. Look at the Go jeep website for a walk through on cleaning it. i broke two trying to get them off, kind of a PITA

Still, there's only 1 person that suggested another thing, jeepfreak1020 with the Torque Converter Clutch Solenoid idea.
:confused:

NSS is bullsh!t. I got a new one from a friend at Chrysler. NOT THE PROBLEM! But thanks for leading me to believe that was the problem. It was an un-necessary pain in the ass. THX!!

(n)

How do you know that your Jeep isn't in overdrive?
 
NSS is bullsh!t. I got a new one from a friend at Chrysler. NOT THE PROBLEM! But thanks for leading me to believe that was the problem. It was an un-necessary pain in the ass. THX!!

Are you going to insult everyone that has listed suggestions that don't work?

I believe I found the problem. I think you need a driver mod.
 
Based on past driver history of failure I would say this unit is the dana 35 / gm 2.8 v6 of the family.

The aw4 is a pretty durable transmission... at least for an autotragic.
 
NSS is bullsh!t. I got a new one from a friend at Chrysler. NOT THE PROBLEM! But thanks for leading me to believe that was the problem. It was an un-necessary pain in the ass. THX!!

Sounds like you need to have a brew and spend a day on the interwebz, bro.

/\ This... There is alot of useful info here man. You have to remember.. You asked NAXJA for help, and the guys here gladly gave you info that they themselves would have gone through if in your situation. I'm pretty sure no one here is trying to lead you on a wild goose chase.
 
NSS is bullsh!t. I got a new one from a friend at Chrysler. NOT THE PROBLEM! But thanks for leading me to believe that was the problem. It was an un-necessary pain in the ass. THX!!

I can't help it if you won't follow reasonable advice, apply logical troubleshooting techniques, or do your research on the Google. Instructions on how to clean and adjust the NSS are here on NAXJA and are easily Googled.

A complete JEEP AW-4 Diagnostic and Service Manual with test procedures and trouble shooting charts is also easily located.
 
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