Minor parking brake issue?

[OriginalBigAl]

My normal exiting the driveway is as follows : get in car , let the system boot up whilst fastening seatbelt, Press brake and put into neutral ( the parking brake auto disengages? ) let it roll backwards down the hill controlling the speed with the footbrake. Swing into the road , brake ,D , go. Sometimes when putting into neutral you need to manually disengage the handbrake? before rolling back. I would have thought the second method is the correct "safer " way of operation, why would anyone want the "handbrake" automatically disengaging when in neutral, especially on a hill. Putting it in D or R from P always auto disengages the parking brake as it should. Any one found similar issues or has any thoughts on this peculiarity?

 

[ReintjeWA]

The only thing I can think of is that the hill holder (correctly) assumes you’re trying to roll down hill? My previous ICE cars all had hill holder assist (or whatever you want to call it) which would hold the car for a little while but not indefinitely.

However the hill holder assist doesn’t use the P brake I think, someone more knowledgeable might be able to shed some better light on this for you

 

[OriginalBigAl]

After re acquainting myself with the manual , its correct , when putting into N from P the parking brake disengages, the sometimes it doesn't is when I've not fasten the seat belt. Sorry kids for wasting your time , don't mix pills with alcohol is all I can say.

 

[ReintjeWA]

After re acquainting myself with the manual , its correct , when putting into N from P the parking brake disengages, the sometimes it doesn't is when I've not fasten the seat belt. Sorry kids for wasting your time , don't mix pills with alcohol is all I can say.

These things are good though, someone may be worried about the same thing, find this thread, and then all will be good.

Slightly (un)related, I noticed the car rolls back immediately when you apply the brake coming up a hill, but don't come to a complete stop. When you come to a complete stop first, then the hill-holder-assist kicks in and holds the car coming of the brake pedal. It's a strange experience in an automatic car, acts like a manual almost.

 

[Matt x power]

Its a shame the auto hold doesn't kick in as soon as you stop, it's not really auto hold anyway, more like a foot operated handbrake

 

[Kithmo]

Why roll backwards in neutral, just put it in reverse ?
IIRC the manual says don't push the car more than 3 mph in neutral, I assume rolling is the same as pushing, so if you roll back at over 3mph you're damaging the HV system.
FYI, if auto hold is on, dabbing the footbrake will disengage it.

 

[ReintjeWA]

Why roll backwards in neutral, just put it in reverse ?
IIRC the manual says don't push the car more than 3 mph in neutral, I assume rolling is the same as pushing, so if you roll back at over 3mph you're damaging the HV system.
FYI, if auto hold is on, dabbing the footbrake will disengage it.

I was thinking about rolling backwards while in Drive, how damaging do you think that could be to the motor/HV battery?

 

[Kithmo]

I was thinking about rolling backwards while in Drive, how damaging do you think that could be to the motor/HV battery?

If it would roll, I'm not sure the motor would like that, it was suggested that just holding the car on a hill in Drive and not on the brake, is bad.
I suggested putting it in Reverse not Drive, because that would not be damaging at all, it just regenerates energy into the HV battery.

 

[siteguru]

I believe the MG4 does not regen whilst in reverse. That's why it's a good way (when clear) to reverse at speed and brake hard to help clean up your pads and discs - especially the rear ones.

 

[ReintjeWA]

If it would roll, I'm not sure the motor would like that, it was suggested that just holding the car on a hill in Drive and not on the brake, is bad.
I suggested putting it in Reverse not Drive, because that would not be damaging at all, it just regenerates energy into the HV battery.

Oh yeah I was sort of talking in general terms, not specifically in response to your suggestion of putting it in reverse, I agree with that advise.

I was wondering how bad it would be for the motor. I don’t really know how that works, would it turn the stator if you turn the wheels? Is there some sort of diff that lets the wheels rotate freely (say on low regeneration for instance)?

Because I often have a hill start on my current commute and noticed the car will quite easily roll back even though it’s in Drive, if you don’t come to a complete stop first.

 

[siteguru]

What drive mode are you in? I find that happens in Eco, and sometimes in Normal, but never in Sport unless it's a really steep hill.

 

[ReintjeWA]

What drive mode are you in? I find that happens in Eco, and sometimes in Normal, but never in Sport unless it's a really steep hill.

Almost always in normal mode. I might try sport mode next time just to see what it does. It’s a give way sign so often times I just slow down until I can see its clear, and not come to a full stop.

 

[Kithmo]

Because I often have a hill start on my current commute and noticed the car will quite easily roll back even though it’s in Drive, if you don’t come to a complete stop first.

I wouldn't think that would do any short term damage, but in the long term, doing it often, maybe.

 

[Logan T]

My normal exiting the driveway is as follows : get in car , let the system boot up whilst fastening seatbelt, Press brake and put into neutral ( the parking brake auto disengages? ) let it roll backwards down the hill controlling the speed with the footbrake. Swing into the road , brake ,D , go. Sometimes when putting into neutral you need to manually disengage the handbrake? before rolling back. I would have thought the second method is the correct "safer " way of operation, why would anyone want the "handbrake" automatically disengaging when in neutral, especially on a hill. Putting it in D or R from P always auto disengages the parking brake as it should. Any one found similar issues or has any thoughts on this peculiarity?

I never use N, nor the handbrake.

Why would you need to?

 

[Kithmo]

I never use N, nor the handbrake.

Why would you need to?

I didn't use to use the handbrake but recently started using the handbrake when stood in traffic so my brake lights don't dazzle the car behind.
N is basically just for moving the vehicle on to a low loader if it's broken down.

 

[Matt x power]

I didn't use to use the handbrake but recently started using the handbrake when stood in traffic so my brake lights don't dazzle the car behind.
N is basically just for moving the vehicle on to a low loader if it's broken down.

To be honest the brake lights aren't that dazling, if anything the tail lights are pretty bright especially on the trophy and x power

 

[Logan T]

I didn't use to use the handbrake but recently started using the handbrake when stood in traffic so my brake lights don't dazzle the car behind.
N is basically just for moving the vehicle on to a low loader if it's broken down.

I never use N, nor the handbrake.

Why would you need to?

(note, I accidentally reported this post, sorry for wasting time)

 

[Bricktop X PWR]

I didn't use to use the handbrake but recently started using the handbrake when stood in traffic so my brake lights don't dazzle the car behind.
N is basically just for moving the vehicle on to a low loader if it's broken down.

And...... I knock it into N when I'm cleaning up the brakes on a long hill once a week.

 

[siteguru]

Indeed - I did this very thing today.