hi there everyone i have just purchased a 1997 cherokee 4ltr auto and seem to be having a few probs with the auto box.firstly when pulling off in drive it sometimes pulls away in what i believe to be second gear and gets stuck in that gear,if i stop and put it through the gears a few times or turn it on and off it pulls away in drive but seems to be just staying in one gear all be it a lower gear,it doesnt seem to change gear at all andsounds like it may be in around 3rd gear.any help and diagnostics would be very much appreciated..

ive had a diagnostic machine plugged into my auto box and it came up with sensor gone to ground or simular,ive taken the sump off changed the sensor and the regulator to be sure but still the problem is there.just to eliterate on the prob,put it in drive and it will start off in second go to third and thats as far as it goes.sometimes i put it in drive and it will start off in first but stay there and wont change,if i stop go through all the gears put it in first and drive it manually up to drive it will get to third and thats it but if i just start off in drive it will only do second and third.ive just spent 51 quid getting it diagnosed and then another 100+ getting the bits incl new oil etc..pls pls can anyone help me resolve this?is it the gearbox brain maybe?and probebly totally unrelated but when driving i get two lots of 3 bleeps then a square shows up on the bonnet sign on the computer and it says coolant sensor bad..related??pls help many thanks kev