Is there a way to reset the transmission ECU or is this a dealer thing?

 

Why do you need to reset it?

 

When I have the vehicle in D,3,2 transmission does not engage however when in 1 it takes off no problem and as speed builds and the rpms build up I manually go thru the gearsuntil indrive, in which it works fine until I come to a stop or close to it, where 1st gear does not engage again and I just coast or have no take off.when I had it in D a few days ago andwhen the rpms got up to around2500the transmission engaged and drove w/ no problem. I only drove it a few miles. I wasjust trying to rule somethings out@ least, as this seems bizarre.

 

What year truck do you have, when was the tranny last serviced?

 

97 4.6 RR. transmission serviced last sept 18. Worked fine til last week, w/ no warning.

 

A 97 doesn't have a tranny ECU, they are regulated by a cable beibg a mechanical shifting tranny.
Have you recenty moved any of the cables? I would check both the shift cable and the kick down cable for proper adjustment.

 

No, haven't adjusted any cables. The only other issue was the transfer case chain seemed to need replacing as it was making the ratcheting sound when given hard acceleration. Not sure how to check the adjustments on the shift cable or kick down

 

Been awhile since I have done much with Range Rovers, but are you sure yours has a chain, I don't think it does.

 

P38 Range Rovers all have Borg Warner transfer boxes, and they do have a chain . Yours is shot if its making that dreaded ratcheting noise.
If you've been driving it too long experencing that sound ,your transmission most likley has ripped apart the sprag clutch inside the forward drum, it happens when the transfer box slips suddenly, this is bad news if you keep the car (expensive) If I were you I'd make good friends with somone that works at a trans repair shop.
Only other thing that might be happening with your trans, if the t-box is constantly skipping the trans wont shift propperly because it uses input and output speeds to determin shift points.
DONT DRIVE THAT ROVER UNTIL THE T-BOX GETS FIXED FIRST !

 

Thanks guys. I am getting the transfer box fixed this week. I am trying to disect this as much as possible due to i want to be prepared in case the transmission shop tries to drill me on other stuff. I haven't been driving it however, that one time that it was in Drive and had no response(there were no lights nor messages displayed) but when the rpms hit around 2200-2500, Drive engaged and the gearbox fault message popped up, i did drive it around the block a couple times gently w/ no ratcheting or problems w/ drive engaging (even @ slow speeds). I accept that my transfer box needs attention however, are there any ways to test if the sprag has went out? thank you