Erratic shifting trans

I have a 2001 ZTS w/Vetec with 62k/kms on it.
This week the autotrans started to shift very erratically upon fast accelleration such as passing or on-ramps to highway speed. What happens is that it gets to the point where it wants to shift up and then pulses back and forth between the higher and lower gear. ( 3-4,4-3,3-4,etc). I have had to resort to slower accelleration and I find if I back off the throttle at the shift point and ease it up it will shift.
I think that it has an electronic problem rather than mechanical, but I don't know.

Have you had similar probs or any advice to offer?
Thanks
irdave

There was a similar thread on a poorly shifting auto trans not too long ago...you may want to email the person to see if he got anything resolved. Beyond that, I really can't help much as I haven't heard about many problems with the Focus ATX. Sorry.
BTW-VTEC is Honda's variable valve system...what you mean is Zetec, which is the Ford motor in some of the Foci:)

I would guess the solenoid that fires to make the shift to fourth is going bad? That seems to make sense to me. I believe there are three of them, all fire for fourth.

OD switch, does it have this? A poor/worn connection on this button could cause a problem too.

The ATX does have an overdrive button on the shifter.

I had the same problem on my '03 ZX5. It always shifted hard and became worse over time. Then it starting shifting from 4th into 3rd on the highway. The dealer replaced something in the tranny, it wasn't called the solenoid although i think that's what it was just called a different name. luckily i had about 1k left on warranty. otherwise it would have been a big bill. they had to drop the tranny and put new fluid in it. they actually did the job twice as the new part immediately did the same thing.

the focus is a cheap car. it now has 76km and it needs a 2nd set of brakes. the exterior handles are difficult to open. just this week the battery light came on so now i need a new alternator. no more warranty but still payments for 2 more years. this thing is going to break me.

Mine was doing the same thing (I was the one with the bad shifting transmission). It would jerk your brains out sometimes when you would floor it. It also was slipping when changing all the gears. Took it to ford, said needed new transmission, 2500.00. Took it to independent shop, said same thing, that it had low pressure due to worn clutches, 1500.00.
Found a used tranny with 49K on www.car-part.com for 350 and got someone to put it in for 300.00. Shifts like new now.