MG5 complete failure after wet road

[thejpster]

Our MG 5 continues to be a pain. After CarPlay died and the radio kept rebooting, now we have a complete HV system failure. It was towed to Peterborough but they can’t look at it for several days.

Full HV shutdown whilst driving, a short while after going through a minor flood. I’m told it was about 75mm deep, it was crossed slowly and carefully using the crown of the road as the highest point. Lots of traffic and every other car got through fine, even a classic Mini. But ours got through and died a few seconds later on the other side.

MG Assist disconnected the 12V and cleared all the codes but as soon as the HV starts up it falls and shuts itself off. They tried multiple times before giving up.

What kind of car can’t handle a few inches of water?

We talked to the insurance but after hearing “water” and “EV” they immediately wanted to declare it a total loss. We’re going to wait to see what the garage say before taking that route. It shouldn’t have failed so I think it might be a warranty claim. Or maybe it’ll be happy once it has dried out and they stick a bit of WD40 in the sockets?

 

[pollenface]

I'm wondering if it's a contactor issue

A lot of videos online of EV's going through water over the windshield and not stopping

 

[Fokmg]

I am very sorry to hear about your problem.
Living in Sunny Wales I encountera lot of rain and floodwater. The other dayI drove through several areas of flooded road (at least 100mm deep) I had no problem. I dont know if there have been any design changes that affect the problem but for nearly 3 years my SR MG5 has been very good.

I hope they manage to sort your problem out, I remember bending 3 conn rods on my Fiat Punto when it injested water in a flood ;- no fun !!

 

[5teep]

May be water got into the charging port and the system sees an issue though I've recently driven through floods much deeper than that without any problems.

 

[Alb]

75mm is insignificant, particularly so at slow speed.
Perhaps the failure is unconnected?

 

[dragon2611]

May be water got into the charging port and the system sees an issue though I've recently driven through floods much deeper than that without any problems.

I'd be more worried about a bad seal on the battery, if waters gotten in there then it's a major problem.

Given the location on the bottom of the car you'd like to hope the batteries are well protected against water ingress but that's not always a given.

 

[PeterHR2]

I can confirm that my FL MG5 had no issues negotiating water at least 6 inches deep in the recent local floods (and that's generally as deep as I'm prepared to go just in case I start to float away!). My neighbour's electric mini similarly had no issues negotiating a similar depth or greater... except she lost all the hub caps!

 

[5teep]

I'd be more worried about a bad seal on the battery, if waters gotten in there then it's a major problem.

Given the location on the bottom of the car you'd like to hope the batteries are well protected against water ingress but that's not always a given.

The battery connector is up near the bonnet, next to the washer refill tube and it's rated ip67 (submerged to 1 meter for 30 minutes)

 

[dragon2611]

The battery connector is up near the bonnet, next to the washer refill tube and it's rated ip67 (submerged to 1 meter for 30 minutes)

But the HV pack itself is on the bottom of the car, hopefully MG's are better sealed than Teslas which have valves in the pack and have indeed suffered with water ingress, mind you the tesla ones seem a bit of an odd design that seems to get full of dirt and then not close properly.

 

[thejpster]

If water has gotten into the battery on a 3.5 year old car with FMGSH then surely that’s a warranty claim?

 

[5teep]

But the HV pack itself is on the bottom of the car, hopefully MG's are better sealed than Teslas which have valves in the pack and have indeed suffered with water ingress, mind you the tesla ones seem a bit of an odd design that seems to get full of dirt and then not close properly.

The whole battery pack is ip67 rated, not just the connector. A couple of weeks ago during the big rain I drove through flood water that washed up over the bonnet. Was worried for a while but there have been no issues at all since.

 

[MickeySw]

The whole battery pack is ip67 rated, not just the connector. A couple of weeks ago during the big rain I drove through flood water that washed up over the bonnet. Was worried for a while but there have been no issues at all since.

I agree, but it’s also very unlikely that this is just an unfortunate coincidence. A more plausible explanation would be that the IP67 seal is compromised somewhere underneath the car and should be rectified under warranty.
Said that, I’m not very hopeful that this will be sorted quickly by MG, maybe a write off will be the lesser evil?

 

[thejpster]

Dealer looked at it today. They can’t clear the fault codes and have no idea what’s wrong with it. They are waiting on a response from MGUK.

 

[MickeySw]

Dealer looked at it today. They can’t clear the fault codes and have no idea what’s wrong with it. They are waiting on a response from MGUK.

I would not be surprised if the HV fuse blew due to a short. What I’m worried about is that they will just replace it without looking for the root cause…

 

[thejpster]

Dealer says they put a new 12V battery on it and it’s mostly fixed. But there’s still a few codes they don’t understand.

I’m baffled as to why, and £280 poorer so far (plus the £300 hire car).

Edit: ok apparently it fixed itself but they want to put a new battery on it? I have no idea what is going on.

 

[EVsince2016]

Our MG 5 continues to be a pain. After CarPlay died and the radio kept rebooting, now we have a complete HV system failure. It was towed to Peterborough but they can’t look at it for several days.

Full HV shutdown whilst driving, a short while after going through a minor flood. I’m told it was about 75mm deep, it was crossed slowly and carefully using the crown of the road as the highest point. Lots of traffic and every other car got through fine, even a classic Mini. But ours got through and died a few seconds later on the other side.

MG Assist disconnected the 12V and cleared all the codes but as soon as the HV starts up it falls and shuts itself off. They tried multiple times before giving up.

What kind of car can’t handle a few inches of water?

We talked to the insurance but after hearing “water” and “EV” they immediately wanted to declare it a total loss. We’re going to wait to see what the garage say before taking that route. It shouldn’t have failed so I think it might be a warranty claim. Or maybe it’ll be happy once it has dried out and they stick a bit of WD40 in the sockets?

I've done 500mm in mine without any issues and they are IP rated for 1m water depth for 30 mins so clearly a defect.

 

[thejpster]

I’m picking it up tomorrow morning. I guess they either found a way to clear the remaining codes or MG told them they were safe to ignore. The bill is £330 but I’m definitely going to ask why it isn’t a warranty repair on a detective vehicle.

 

[Hils]

Our MG 5 continues to be a pain. After CarPlay died and the radio kept rebooting, now we have a complete HV system failure. It was towed to Peterborough but they can’t look at it for several days.

Full HV shutdown whilst driving, a short while after going through a minor flood. I’m told it was about 75mm deep, it was crossed slowly and carefully using the crown of the road as the highest point. Lots of traffic and every other car got through fine, even a classic Mini. But ours got through and died a few seconds later on the other side.

MG Assist disconnected the 12V and cleared all the codes but as soon as the HV starts up it falls and shuts itself off. They tried multiple times before giving up.

What kind of car can’t handle a few inches of water?

We talked to the insurance but after hearing “water” and “EV” they immediately wanted to declare it a total loss. We’re going to wait to see what the garage say before taking that route. It shouldn’t have failed so I think it might be a warranty claim. Or maybe it’ll be happy once it has dried out and they stick a bit of WD40 in the sockets?

So sorry to hear this. I’ve driven through floods and had no issues and think they were deeper than this too. Was really careful and went slow etc and do try not to just like any other car would. Interestingly the diesel all failed and mine didn’t. Hope you get sorted soon.

 

[Wendwell]

I’m picking it up tomorrow morning. I guess they either found a way to clear the remaining codes or MG told them they were safe to ignore. The bill is £330 but I’m definitely going to ask why it isn’t a warranty repair on a detective vehicle.

Please keep me updated on the response to your warranty claim. Good luck with it.

In case this isn't obvious to you, try and get them to put in writing anything used to avoid warranty cover. Failing that, send an email with their reasons and ask them to confirm.

 

[Redoralive]

Our MG 5 continues to be a pain. After CarPlay died and the radio kept rebooting, now we have a complete HV system failure. It was towed to Peterborough but they can’t look at it for several days.

Full HV shutdown whilst driving, a short while after going through a minor flood. I’m told it was about 75mm deep, it was crossed slowly and carefully using the crown of the road as the highest point. Lots of traffic and every other car got through fine, even a classic Mini. But ours got through and died a few seconds later on the other side.

MG Assist disconnected the 12V and cleared all the codes but as soon as the HV starts up it falls and shuts itself off. They tried multiple times before giving up.

What kind of car can’t handle a few inches of water?

We talked to the insurance but after hearing “water” and “EV” they immediately wanted to declare it a total loss. We’re going to wait to see what the garage say before taking that route. It shouldn’t have failed so I think it might be a warranty claim. Or maybe it’ll be happy once it has dried out and they stick a bit of WD40 in the sockets?

Doubt the water had anything to do with it. 3 inches wouldn't even wet the bumper.