98 cherokee won't shift into overdrive

bnrboy775 · 09-15-2008, 07:45 PM

Okay, So i'll start from the beginning.. i've been having problems with my NSS off and on... I find the write up on here on how to clean it out and follow the directions exactly. I get it all put on and then a couple weeks later i stop at the gas station and walk out to start it and turn the key and nothing.. so i had a mechanic look at it and we spent an hour adjusting it and getting it to work perfectly. reverse lights work and everything. Then about 5 days after that i am pulling a trailer. i dont have trailer lights so i ask the same mechanic to help me figure them out, well we worked on that for about an hour and all we could get was the parking lights to work. I get back into my car and start er up and the check engine light comes on... I just ignore it for a couple days.. and then i finally take it to a show to get the codes scanned... Well i had 4 codes come up... One was the evap sensor open/ shorted... a/c compressor relay open/short.. the third i don't remember. and the fourth was a transmission fault code. since then i have noticed that my jeep is not shifting into overdrive, and the a/c is not working at all... So i park it and drive my other car... I get back in it today and start driving up the road and my check gauges light comes on... my volts were reading at like 9.5.. so i turn around immediately thinking my alternator was shot... i pull in the driveway the shut it off fully expecting it not to start again.. It starts right up and the volt gauge is reading just under 14... So i shut it off again.. and start it back up and its reading 9.5 for a bit then shoots up to just under 14.. I do this same process several times and each time it alternates between 9.5 and 14..... and so i know this is a lot of information but i have described everything so you guys can maybe tell me what's going on with my jeep... Its a 1998 cherokee sport, 4.0, automatic...

123mylesl · 09-15-2008, 08:06 PM

I had a similar problem with my xj and it kept draining the battery. Make sure their is a ground running off the negative port of the battery. If its not that it may be a short, I also had a similar problem when my distributor cap was loose because it throws the timing off.

bnrboy775 · 09-15-2008, 08:13 PM

it doesnt really drain the battery, it starts fine everytime....

bnrboy775 · 09-15-2008, 08:28 PM

now i remember what the other code was... It was the electric fan relay open/shorted... my main concern in this post is the overdrive thing... what's causing it?

jackdup · 09-16-2008, 03:44 PM

this is a stupid question but do all cherokees have overdrive? what is overdrive on these? 4th gear...is it a three speed with overdrive? or a four speed...or a four speed with overdrive? ive been confused with this since i bought it and i was just wondering because i consistantly get 15 mpg even when i baby it with a free flowing muffler..no tailpipe...rustys intake and throttle body spacer..and the accel super tune kit..i thought i should be getting alittle better..idk

bnrboy775 · 09-16-2008, 03:48 PM

I dont know exaclty... all i know is on my shifter it is set up like this
P
R
N
OD
3
12

**Ed Rico** · 09-16-2008, 04:05 PM

The AW4 has four forward gear ratios, 3rd is 1:1 and 4th is overdriven at 0.75:1. It's consistently referred to as a 4-speed automatic trans.

-Ed Rico

jackdup · 09-16-2008, 05:22 PM

ok thanks ed rico..i was just really confused at that because it has always been referred to as 4 speed so i didnt get it..but now i do! thanks man

jqstringer · 09-17-2008, 09:17 PM

I have the same problem of my cherokee not shifting into overdrive. What is the problem?

TreddyoXJ · 09-18-2008, 12:09 AM

I had a couple of your symptoms last spring. Battery gage was freaking out and no over drive, occasional not-starting, etc. Cleaning that NSS DOESN'T always work. Cleaning it can work, but didn't work for me. Fixed the issue for a few days, and then it came back. The overdrive is linked to the NSS. Unplug that harness any other day, arc the starter, and you will notice that you don't have over drive. BUY a new NSS. They are roughly $200, maybe a little less. It will fix that problem, though!

With the battery, that could be a sign of your battery going out. When it has trouble maintaining the charge while driving, the car will try and send all the power to the battery, resulting in the gauge going crazy and the "check gauges" light coming on. Have your battery tested to see if that is one of your issues. It might also be a bad ground and that is something you need to check for.

One the other issues, no A/C or fan, I might check the fuse box. Other than that I've got nothing for you.

Don't you love Jeeps?

jqstringer · 09-20-2008, 11:39 AM

I had a problem with my ac and rewired a bypass and now it works great. The problem I had (and still have without the bypass) has to deal with the relay in the power distribution center on the right side next to the battery.

Try replacing it, if that does not fix it try what I did to bypass the system.

------------------------------------------------------------

There are three wires going to the relay - a ground, a constant hot wire and one that is only hot when the key is on and the ac engaged.

The problem I have is the wire that only has power when the key is on is not getting any power.

You can test the system and determine if this is your problem real easy. Remove the casing from the relay. With the relay plugged in, push the connection point together. If you hear the ac clutch engage this is your problem (you should clearly hear a click as it engages).

I ran a bypass wire from the auxiliary power supply next to cigarette lighter to the wire causing the problem in the distribution center. The auxiliary power supply is on its own system with a large 25 amp fuse in the fuse box so it is safe and is only active with the key on. I also incorporated a toggle switch to manually turn the ac on and off and made a place for it on the dash (it looks nice – almost factory). I ran the wire behind the right fender and into the cab through the passenger door jam.

If you do this however, you will has have to continue the bypass wire to the electric fan on the radiator to ensure it engages with the ac – otherwise it will not come on and your vehicle will over heat.

I know it did not fix the problem the right way but it works and the only cost was the wire and switch about $10. (be sure to use a heavy enough wire gage)

RogueXJ · 09-20-2008, 12:21 PM

let me ask: is it never going into overdrive, or is it slipping out of overdrive? If it never goes, then it might be as suggested above. Whereas if it slips out of overdrive....could be a transmission solenoid. Mine turned out to be a solenoid that was dirty and got it replaced and now it goes into OD every time.

blacky_j · 02-19-2009, 07:32 PM

is replacing the transmission solenoid easy?

rustylugzz · 02-19-2009, 11:36 PM

i could be wrong but i think youre confusing od with the torque converter locking up which is the final shift you feel at approx 45 mph. when mine did this my tranny had to be rebuilt but i suspect i got ripped off but it had 285,000 miles so i was due i guess

Rollin · 02-20-2009, 05:54 AM

How old is your battery and alternator? I would bet money replacing that combo would fix the problem. PCMs are very very sensitive to voltages. The fact that all of this happened just as your guages indicated problems with your charging system would lead me to believe that either your alternator or battery is bad. In my experience, the battery guage doesnt sway away from 14 or 13 volts for any reason. Its indicating a problem.