Xc90 T8 throttle latency / drive delay issue

[jshack]

Hi,

I have a 2016 Xc90 at 35000miles which has started to give me problems. About 6 months ago I had a hybrid failure message and the car wouldn’t start. That was “resolved” with a software upgrade at the dealer and no problems since.

However in the last few days the once fairly seamless transition between electiric and petrol power has become very pronounced to the point of being dangerous. If I put my foot down to pull out of a junction in hybrid mode the car loses power and seems to pull back before you can hear the petrol motor kick in and then it shoots off.

This happens in all modes as it takes up drive on the petrol motor but more pronounced in hybrid/pure modes.

All still under warranty thank goodness and I’ve got it booked into the dealer next week however they’ve told they donlt have any hybrid techs available
Until we’ll feb - that being another issue!!

Has anyone experienced anything similar or got any ideas about what might be causing this?

Thanks
James

[Philip Fisher]

Mine does and always has done this, but to a very minor extent. Sometimes when sitting at a busy roundabout I pop it in Power mode and then it pulls away seemlessly. However in hybrid form sitting with engine off there is a delay, then the power kicks in and off I go. At part throttle it can sometimes cause juddering as the car seems to struggle with whether it is starting the engine or not.

Yours sounds like a more extreme version of - what I assume to be - this normal characteristic.

[jshack]

Hi Philip - thanks for your reply.

Thing is it didnt do this in he preceding 35k miles or so. Yes you can always tell
When the petrol engine takes over and there is a momentary blip which is barely perceptible but this is like its applied the brakes or the regen for about a second before you can hear the engine start which is an altogether different experience. And dangerous on a roundabout / busy junction.

I half wondered if it could be a lazy battery/ starter motor. Anyway I’ll see what the dealer comes back with.

With the exception of the hybrid failure error (software update at service) the car has been totally dependable, the odd random dash warnings for parking sensors or indicators fixed with a reboot :-)

Thanks
James

[MaDProFF]

I must admit, my first ? would be why would something work for so long, and then be an issue, and then a software update solves the problem, has the software broken, I do not think so. Software updates to repair, tend to mask issues till they get worse.

I know I have a XC60 T8, and MY19, so different but is it really that different? But it is seamless pulling away, as you would expect using the battery, as it is instant torque, as I would expect yours to be on battery power.

[Philip Fisher]

So some more thoughts.

Does it definitely happen in all modes? Including Power Mode?

If you click the charge tab, or put in Power Mode does the engine start and run cleanly? Can you then rev the engine in neutral without hesitation?

If it hesitates when pulling away in Power Mode then it would appear to be entirely an ICE problem and would rule out the generator/starter unit.

[Deman77]

Not t8 specific but can be applicable. Reset your gearbox learning logic by switching to off-road and then speeding up to 30 or so till it goes into comfort. It improves gearbox laziness for me as I have multiple users and adaptive programme gets crazy over time.

Failing that I would think knackered low voltage battery. I had all kinds of seemingly unrelated problems when I was having battery issues early on in car’s life.

Good luck

[jshack]

Thanks for everyone's feedback on this and apologies for the late response. It went back to the dealer a couple of times - first for a software update which did nothing and secondly for an ERAD transmission replacement which took about 3 days and totally resolved the issue.

With hindsight I probably mis-described the problem. The transmission on the electric motor was slipping which, like clutch slip in a regular car, resulted in me putting more power down with no forward drive, such that the extra revs were causing the petrol engine to kick in.

Given that the technician immediately diagnosed the problem, there was no quibble about its replacement and i've seen T8's in the workshop perviously with no rear axles, I'm guessing this is a pretty common fault.

Mine failed at ~35,000 miles so if anyone's experiencing any noticeable delays/hiccups in drive I'd recommend getting this checked out asap certainly before the warranty expires as with the labour alone this would be a very expensive job.

Thanks
James

[Haldex]

Judging from post on swedespeed (as there's A LOT more T8s stateside than in EU..) ERAD transmission failure is a VERY common problem..

[Philip Fisher]

Makes my 3 year after market warranty look like a steal then.....

[MaDProFF]

I wonder if they have uprated the ERAD Transmission? or they still fitting the same as keeps failing?