p38 kickdown no longer working

Hi all,
this is a 96 4.6 HSE.

I didn't use the car much at the end of last year and allowed the battery to die.
Having replaced the battery and gone through all the usual window resets etc, the car would idle at close on 2k revs. I assumed this was because the ecu is detecting a lower voltage and so trying to charge it (It used to do this if left for a few weeks anyway).

I've been using it fairly regularly and its now idling around 600 to 800, but I am left with no kickdown. It won't kick down in any gear at any speed, but will manually shift just fine. The sport mode seems to make it hold on to a gear slightly longer, but not much. It seems that the throttle position has zero effect on the change points.

Is the kickdown purely manual ?
Or is there something magical I need to do in order to reset the throttle position sensor or something ?

Any advice would be most helpful, as I'm currently driving it by manual shifting when necessary.

Thanks in advance.

Cheers,
John.

When I get a transmission alert on the dashboard, the same thing happens as you have described. I Just turn off the ignition and turn it back on and then the auto works as normal.

Im guessing that because your box works when shifting manually, there is actually nothing wrong with the transmission. That being, the problem will be with the sensors/wiring that is associated to it. Bad earth hopefully?

Check your TPS sensor and the plug/connections.

thanks people.

I gave the connector a wiggle and went from no kick-down to kick-down at any throttle position :doh:

Anyway, that seems to point at either the wiring or the TPS itself, so at least I know what to play about with now, thanks