hi all , i have had this problem for a while now not sure if its a real problem its just annoying as all hell.

bf xr8 6 speed auto (can change gears up in tiptronic mode but not downshift)

anyone have any ideas it would be much appreciated

cheers......

Hey man,
I own a bf xr8 sedan and have the ford workshop manual at home. I had a look through the diagnostic guideline for the zf 6 speed, and at a rough guess it sounds like an electrical fault, either with a sensor or wiring between the shifter and TCM (transmission control module). Hard to say though without the diagnosing software mechanical workshops have. With this you can connect to the TCM, and using fault codes it can a least point you in the right direction for the cause of the problem. Heres what the manual said:
"Possible Cause:
Wiring between shifter printed circuit board (PCB) and TCM defective or damaged. Incorrect software programmed TCM/PCM PCM parameters incorrect i.e. tyre size, axle ratio etc
Defective shifter mechanism Defective PCB Defective TCM Defective PCM"

"Transmission fault
If a major fault develops, the transmission may automatically operate in a ’limp home’ mode to enable the vehicle to be driven to an Authorised Ford Dealer for repair. During ’limp home’ mode, the transmission will still operate but with a limited operation dependant up on the fault detected and the transmission selector indicator on the instrument cluster will flash. Limp home mode may also be engaged if the battery charge falls below 9V.
With limp home, dependant up on the fault, the shift patterns can change and some of the gears may not be available."

Both of these paragraphs are copied straight out of the manual. Hope this helps man, best bet might be to take it to a workshop where they can a lease hook up the com adapter and access the fault codes...could be somthing simple like flash files, calibrations, limp mode etc.

if up is working but not down (or the other way), it indicates the trans is working fine, as is the wiring.

The problem is probably the in the shifter unit itself.

It uses a magnet on the shifter stalk, that when moved, triggers hall effect sensors that send the signal to the TCM in the box.

the magnet may not be aligned properly (you bashed it too hard one day?), or the hall effect sensor for 'down' is broken, you'll need a new shifter unit PCB.

the hall effect sensors are the little black bits (6) on the bottom of the PCB (top here in this up side down shot).

You'll note there's a sensor for each of (top right) P, R, N, D, Dperf and Up (bottom left).

Down doesn't have one, as it is triggered by the fact none of the sensor will see the magnet when you move the shifter into the down position. So Down not working would indicate to me the magnet is not in alignment, so the Dperf sensor still sees it even when you push forward for down (and therefore thinks it's in the 'neutral' (not N) position between up and down.


edit: I occasionally have an issue with down on mine, it's not consistent though, and I have other options (steering mounted shifter buttons), so I haven't bothered to investigate.

thanks heaps for your help fellas ill have a look into it this weekend/pull it apart and possibly break more stuff lol..

I got exactly the same problem with a 2009 XR6T 120,000km, so thanks for that detailed explanation. Can you post how you get on (and what it costs), as I don't really want to give it to Mr Ford and say "fix it". that's got me into $$$ troubles before. Cheers Stu