Autobox hill descent mode

[john adam]

Greetings
The descent mode on our 2.5 V6 autobox has stopped working, everything else is working normally. Advice would be appreciated.

[BrianA]

When was the last oil/fluid change?. Recommended change interval is 6 years.

[SD1too]

Originally Posted by john adam

The descent mode on our 2.5 V6 autobox has stopped working, everything else is working normally.

In that case I doubt that you have a transmission fault as such John. The response of automatic gearboxes is highly dependent upon engine tune, and two things in particular have quite an impact upon performance. The first is a fully operational VIS system (including the balance flap) and the second is that the breather system pinholes in the camshaft covers are cleared of hard carbon deposits which block them. When I corrected these two things suddenly my engine appeared to gain another 50 bhp and the gearbox downchanges became much livlier. I did nothing to the automatic transmission.

Simon

[john adam]

Thanks for your helpful comments. The fluid was changed in 2010.