I have a 98 sport Automatic (3 speed) 4WD V6 with 90,000 miles on it. Recently the tranny is acting up. It doesn't upshift on lower gears. From a stop when I push on the throttle the car accelerate just fine but it doesn't upshift to the next gear. The RPM go up all the way to 4,000 and still nothing. As soon as I let the throttle go the RPM drop down and the tranny shifts to the higher gear. At higher speeds/gears the problem is not there.

Following this issue the check engine light came on. Ran the scanner and found a P0751 code. Checked the code description as "Overdrive off switch input too low for more than 5 minutes".

As anyone had anything like this happening before? If so, how did you fix it? I cannot find anything about O/D switch nor code P0751. Any help is highly appreciated.

Items checked so far: Engine and battery grounds, TPS range Low 0.787 and High 3.89, adjusted Throttle valve (TV) linkage, checked and cleaned the NSS switch, changed automatic transmission fluid and filter.

I'm really running out of ideas please help if you can.

 

i'm just gonna suggest a good tranny service to start with, most of the time thats fixed most of my shifting problems, except on my neon (go figure lol)
also, crawl underneath and check for loose of frayed wires going into the tranny case, might have knocked something loose in the woods or something.

 

Read this.https://www.cherokeeforum.com/showth...ble+adjustment