XC60 Geartronic gearbox problem

[GJB]

Have a strange effect happening when car is hot and in a traffic jam .
With car in gear and foot on brake put on hand brake foot off foot brake car lurches forward and weight is put on hand brake ,can also happen when in traffic foot off of brake and car lurches forward before I manage to get my foot on accelerator. This only happens when in traffic jam.

[wimorrison]

This doesn't sound like a gearbox issue to me, rather that you have a braking issue.

The brakes hold on the rear using the same pads whether it is foot or EPB and if the car move when your release the footbrake after having applied the EPB it says to me that the rear footbrake is not engaging fully.

[Agouti]

Could it also be idling high or otherwise have unusually high motive force when idling? Torque converter or oil issue? Geartronic overheating?

It's just that "lurching" while idle in D doesn't sound like normal behaviour to me.

[wimorrison]

I noticed this morning that when I have my foot on the foot-brake and then I apply the EPD I can firstly here the EPB 'winding on', but also the foot-brake pedal goes down a tad. When I release the EPB with my foot on the EPB the pedal rises - the movement is subtle but most definitely there confirming the relationship between the 2 systems.

Do you also find this subtle indication?

[Fursty Ferret]

I would say that this is normal - the parking brake only operates on the rear wheels, so when you release the brakes the front wheels will turn under idling power until held by the rear wheels. There's a degree of flex in the tyres and suspension which accounts for the jerk forwards.

Personally I wouldn't use the EPB while leaving the car in D. Slip it into neutral first or just keep your foot on the brake.

[GJB]

Originally Posted by wimorrison

I noticed this morning that when I have my foot on the foot-brake and then I apply the EPD I can firstly here the EPB 'winding on', but also the foot-brake pedal goes down a tad. When I release the EPB with my foot on the EPB the pedal rises - the movement is subtle but most definitely there confirming the relationship between the 2 systems.

Do you also find this subtle indication?

No has has now got worse and it's back to dealer again (this only happens when engine is well up to temperature for instance when towing or after a good high speed run on motorway)

[GJB]

Originally Posted by Fursty Ferret

I would say that this is normal - the parking brake only operates on the rear wheels, so when you release the brakes the front wheels will turn under idling power until held by the rear wheels. There's a degree of flex in the tyres and suspension which accounts for the jerk forwards.

Personally I wouldn't use the EPB while leaving the car in D. Slip it into neutral first or just keep your foot on the brake.

Not normal as has only occurred over last 4-6 weeks and does not happen all the time.

[Agouti]

I tested my car - parking brake on, foot on brake to get it out of P then foot off and shift into D. Also tried D to R to D. The car gently settles against the hand brake with the nose rising but there is certainly nothing resembling a lurch or surge.

Maybe there is something loose in the rear brake assembly?

[GJB]

Brakes have been checked and all OK

[jackthehat.co.uk]

You will need the gearbox adaptions reset at the main dealer. It will cure the problem instantly. Cost approx £90. If the problem re-occurs after a few weeks then the valve body in the gearbox is faulty. £2500-£3000 fix at a main dealer. I've just got rid of my XC60 for a similar fault. These gearboxes are appalling.