2.8 auto wont select 5th or 6th

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

Interesting issue arose . Driving from Melbourne to Eden on Monday. This is very flat across Gippsland. 35 deg, 100kph on c/c, strong tailwind. After 2 or 3 hours of this I noticed that it had changed back to 4th and would not go into 5th or 6th either on c/c or in Sport but would select all of 1-4. No lights on dash, temps normal.Only driver and no load. Hmm. Stopped and turned the motor off for a few minutes. On restarting all was normal and has remained so all the way back to Sydney. Car has done 8,000 km. Anyone experienced this? Any thoughts?

[120D4D Avid PP Poster! Find all posts View Profile Close 120D4D]

Was is doing a burn? Warm ambient and DPF burn will trigger the ECU to hold a lower gear.

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

YES now I think of it. When I stopped it was idling at burn idle speed of about 900 rpm. It had been mainly in 6th gear at about 1600-1700 rpm so this makes sense but i didn't notice it happening going down the Hume at 110 a few days before [ but it was a lot cooler]. One to watch.

[OzDriver Member Find all posts View Profile Close OzDriver]

Mine did this also - but only once soon after collecting it from new. 99% it would be a DPF burn.