Gearbox not dropping to 6th when in cruise?

[Rusty]

I had some weird issues with the gearbox / cruise control coming back from Sydney on the weekend.

It seemed to get stuck in 5th gear quite a bit, even down hill. I first noticed because the average fuel economy was around 12/100 which was unusually for the highway.
It was also revving around the 2500 mark when normally it would be around 1800.

The only way i could fix it was use the paddle shift to drop it back to 4th, then put it back up to 6th again.

It happened 5 or 6 times on the trip, the gearbox was definitely in drive.

[Shaun]

Hi Rusty,

Was the car maybe in power mode? I would think it would hold the gears in the zone of most torque as opposed to trying to save fuel?

[davidd]

If it's in drive and going down hill it should up shift of course. From your description a call to your dealer service desk may be in order mate. Only cost a phone call to find out.

[davidd]

I had some weird issues with the gearbox / cruise control coming back from Sydney on the weekend.

It seemed to get stuck in 5th gear quite a bit, even down hill. I first noticed because the average fuel economy was around 12/100 which was unusually for the highway.
It was also revving around the 2500 mark when normally it would be around 1800.

The only way i could fix it was use the paddle shift to drop it back to 4th, then put it back up to 6th again.

It happened 5 or 6 times on the trip, the gearbox was definitely in drive.

Mate I read that cruise control was on. Possibly downhill it drops down a gear for engine braking. Check with someone else who has an auto. If they don't have the same thing happening ring dealer. They are there to help.
Cheers

[Shaun]

Yep, I reckon that sounds like the most plausible answer...

[Fortunate]

Mine does that too, auto and once on down slope, cruise on grabs 5th and holds for a bit.

[TanyaG]

Yep, mine too.

[Fuses]

Its part of the euro 6 emmision standard.They will not fix the problem as to maintain the euro 6 certification they require the engine under certain load to rev up to reduce particulate pollution. Even though it is going to use more fuel its actually less polution. Hence I just I just ordered a Torque lock up kit from Richards Auto Electrical in Adelaide. Im done with it so frustrating when driving it the way it is

[Spook1205]

We are currently under Euro 5 standards hopefully it will be a while before they implement Euro 6.
I have noticed this a few times too and it's happened not just on downhill engine braking.
my thought process thinks vehicle has not met all conditions to hold it in 6th gear, at first I thought maybe it's just a very passive regen because it's doesn't last long but it's done it whilst having scope on DPF and DPF is very clean. If was on a regen and needed higher RPM it wouldn't change after hitting paddle shift just like it won't forcibly downshift if road speed too high.
Its interesting why this happens. Just because we like it to be in 6th doesn't mean the TCM wants it to be.