New Owner, Unfortunately an issue.

[rolydog2001]

We picked up our MG5 LR Excite on Friday, Unfortunately (for my wife) it left her stranded for a short time today. It moved forward a couple of feet from a parking spot then died. I gave some directions from the phone i.e turn it off and on/ unlock and lock etc and fired back into life. Having tested it tonight after having stopped and parked then attempting to drive off it comes up on the dash on powering up: HV battery disconnected along with a few warning lights. Seems to sort itself out after pushing the power button on and off a couple of times.
Was basically wondering if this was a known issue?
Thanks

 

[Dave]

This sort of thing can happen if the 12V battery is low.

 

[rolydog2001]

Just done a search and seems to be a common fault, Unfortunately.

 

[rpannell]

Can also happen if you try to do things too fast or try to start with your foot not down hard enough on the brake. When starting, give everything a little more time.

 

[Jomarkh]

I have had it a few times when trying to gèt moving to quickly, just pause between button presses and turning the drive dial.

 

[Kithmo]

I have had it a few times when trying to gèt moving to quickly, just pause between button presses and turning the drive dial.

Yep, done it myself when I got out of the car while it was in Ready mode and got back in and habitually pressed the start button and accidentally turned it off, then was too quick to turn it back on before it had finished powering down fully. Major warnings on the dash about traction battery not connected etc etc.

 

[MarkLynn]

Happened once to me (trying to do things to quickly) as already said, just stop what your trying to do, turn it all off give to 30 seconds and start again using the correct sequence.

 

[staarek]

We picked up our MG5 LR Excite on Friday, Unfortunately (for my wife) it left her stranded for a short time today. It moved forward a couple of feet from a parking spot then died. I gave some directions from the phone i.e turn it off and on/ unlock and lock etc and fired back into life. Having tested it tonight after having stopped and parked then attempting to drive off it comes up on the dash on powering up: HV battery disconnected along with a few warning lights. Seems to sort itself out after pushing the power button on and off a couple of times.
Was basically wondering if this was a known issue?
Thanks

hi rolydog2001, did you manage to sort it out?

EDIT: sorry, i missed the last bit of your post. Anyway, here's a post from user EVsince2016 which may help in the future

"Spoke to MG today about this & what the fix is.

Answer was: -

Disconnected both terminals, connect the live / neutral cables together, use a clamp or something & within 10 mins the cars capacitors will discharge & it'll reset fully."

 

[Slipstream]

hi rolydog2001, did you manage to sort it out?

EDIT: sorry, i missed the last bit of your post. Anyway, here's a post from user EVsince2016 which may help in the future

"Spoke to MG today about this & what the fix is.

Answer was: -

Disconnected both terminals, connect the live / neutral cables together, use a clamp or something & within 10 mins the cars capacitors will discharge & it'll reset fully."

Sound dangerous to me. As said earlier all you need to do is not be so hastey when starting the car. Make sure your foot is firmly on the brake pedal.

 

[Dave]

Sound dangerous to me. As said earlier all you need to do is not be so hastey when starting the car. Make sure your foot is firmly on the brake pedal.

Totally agree. Advising a customer to disconnect the 12V battery leads and then to connect them together on a car that has a 73kWh 400V battery that has a connection to those two cables (it charges the battery through them) is NOT sensible.

 

[5teep]

Just done a search and seems to be a common fault, Unfortunately.

Common but not a fault, if the car sees the 12v battery as low it won't let you start until it's charged it up a bit. It is possible to confuse the car as others have said, by trying to get going too quickly but it will sort itself if you switch off and try again.

 

[rolydog2001]

Thanks all, just to give a bit of background I am an AA patrol so do know a little. Having had a bit more time to replicate it seems to be if you don't put your foot on the brake pedal it will bring this up. Get in put foot on brake pedal prior to starting then it's fine. Guess it's just a quirk. On the plus side missis loves the car.

 

[EVsince2016]

I've found this. You do have to be careful to push the brake first & hold it when you press start. A few times I got HV battery shut off when I was too quick.

Now I know just to do the brake / start again & it works.

Very easy to get you flustered though!

 

[Kithmo]

Yes a few people get confused by the brake push.
How hard you press it is not as important as keeping it pressed until "READY" appears on the dash.

 

[Lguk]

My yank tank needs the clutch in to start. I assume because they can't be trusted with a manual. I'm so used to that that brake down until started just came naturally. Posts like this are really helpful see before you find yourself in a pickle.

 

[Ozzie1989]

Totally agree. Advising a customer to disconnect the 12V battery leads and then to connect them together on a car that has a 73kWh 400V battery that has a connection to those two cables (it charges the battery through them) is NOT sensible.

Not at all dangerous, the 12v battery is needed to open the contactor for the HV pack. Without the 12v battery this will be open circuit and isolated.

The 12v battery is never connected directly to the HV pack, it is charged through a charging unit which will again be isolated due to the contactor being open circuit.

Even if in the strangest of circumstances the contactor jammed in a closed circuit state, you cannot short circuit the HV battery by joining the 12v leads as the circuitry within the charger wouldn't allow this to happen.

This practice is common to discharge capacitors, and would ensure the various ECUs etc. to be returned to a fully powered down state (think if you put your TV on standby, then turn off the power at the wall, it takes 10 seconds for the LED to extinguish as it drains power from the capacitors).

Joining the positive and negative leads should only be done by someone who knows what they are doing however, as there will be people out there who think that means putting a screwdriver between the battery terminals which it absolutely does not!

 

[Alb]

My yank tank needs the clutch in to start. I assume because they can't be trusted with a manual. I'm so used to that that brake down until started just came naturally. Posts like this are really helpful see before you find yourself in a pickle.

It's a pretty standard setup for any modern car.
Clutch Pedal for Manual and Brake Pedal for Automatic/EV.

 

[rolydog2001]

Not at all dangerous, the 12v battery is needed to open the contactor for the HV pack. Without the 12v battery this will be open circuit and isolated.

The 12v battery is never connected directly to the HV pack, it is charged through a charging unit which will again be isolated due to the contactor being open circuit.

Even if in the strangest of circumstances the contactor jammed in a closed circuit state, you cannot short circuit the HV battery by joining the 12v leads as the circuitry within the charger wouldn't allow this to happen.

This practice is common to discharge capacitors, and would ensure the various ECUs etc. to be returned to a fully powered down state (think if you put your TV on standby, then turn off the power at the wall, it takes 10 seconds for the LED to extinguish as it drains power from the capacitors).

Joining the positive and negative leads should only be done by someone who knows what they are doing however, as there will be people out there who think that means putting a screwdriver between the battery terminals which it absolutely does not!

Totally agree with the above, we call it (at the roadside) a 'hard re-set'
Chris

 

[Dave]

Not at all dangerous, the 12v battery is needed to open the contactor for the HV pack. Without the 12v battery this will be open circuit and isolated.

The 12v battery is never connected directly to the HV pack, it is charged through a charging unit which will again be isolated due to the contactor being open circuit.

Even if in the strangest of circumstances the contactor jammed in a closed circuit state, you cannot short circuit the HV battery by joining the 12v leads as the circuitry within the charger wouldn't allow this to happen.

This practice is common to discharge capacitors, and would ensure the various ECUs etc. to be returned to a fully powered down state (think if you put your TV on standby, then turn off the power at the wall, it takes 10 seconds for the LED to extinguish as it drains power from the capacitors).

Joining the positive and negative leads should only be done by someone who knows what they are doing however, as there will be people out there who think that means putting a screwdriver between the battery terminals which it absolutely does not!

Thank you for the clarification

 

[Tim Falkiner]

Can also happen if you try to do things too fast or try to start with your foot not down hard enough on the brake. When starting, give everything a little more time.

Do not touch anything once you have pressed the start button until you hear the bong and the needle on the power dial settles at zero.