Hey guys, our 05 4.7 has been shifting down when cruising down the highway...mostly when tranny is well heated up after 60 miles of driving. We will be cruising at hiway speed, then it seems like it shifts out of O/D for a bit, then back. First time (2 years ago) it was suggested as a computer issue, so disconnected battery for a while. Cleared it up. 2 months ago, it did it again, but the reset only lasted a week. Now it does it nearly every long trip. This last time, it shifted down a couple, and revs hit high 4000's. Any ideas? It drops to first at 75 mph and bad things may happen.

 

Do any codes show up?
FF

 

Sammy:

How many miles (or kilometers) on your D?

The symptoms you describe could very well indicate a failing TPS or Throttle Position Sensor.

Three torx screws secure it to the throttle body. ~$35 part here in the USA, no doubt a bit more with your Canadian dollar up north.

I would try this first to rule it out. I think you might be pleasantly surprised.

Don

 

Thanks for the replys. Durango has 200,000 km (125,000 mi), and has recent tune up with Throttle body cleaning, new plugs....however original battery. No codes come up with triple key turn (it is just off to on, repeat 3 times is it not?) Hopefully a new batttery and this sensor are a quick cheap fix. It kinda makes sense, we'll soon see. Anything else you can add is greatly appreciated.

 

Actually, on the 4.7, its only two torx screws. Its the same sensor as the older 5.2L and 5.9L Magnum V8s use.

Original battery after 125000 miles on a 2005? I'd get that checked at a reputable auto parts store. My wife's 06 had a battery that was below the recommended amperage (original), and that was at 83000 miles. I also put on a new TPS. Next is the pre-cat oxygen sensor...

 

Jason:

Its been a while since I changed the TPS on my previous 01, so I might be recalling the number of screws wrong.

Sammy:
The TPS is what helps the PCM know what gear to have the trans be in. I am voting on that!

It would not hurt though to have your battery load tested to rule out any issues there also.

Don

 

My 2004 4.7 Did the same thing. Every bridge over pass and bump in the road seemed to trigger it . TPS cured it.

 

I apologize if I came off as a bit of a dick, that was not my intention. I just didn't want the OP to be searching for hours for a mythical 3rd screw.

 

Jason:

No offense taken, and thanks for the polite reply. We all lose a screw now and then......:0)

Don