Failure to start: HV battery shut off

Eclectic

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Canterbury UK
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ZS EV Trophy LR
I have just been afflicted with the battery shut down fault. My ZS Trophy LR failed to boot Friday evening, giving the “HV battery shut off” warning.
I tried all the usual fixes, including disconnecting the 12V for a while, but it just sat there popping up the same failure message.
MG assist were excellent, and the AA Man tried all the things I had, and plugged in his diagnostic machine to clear some 20 odd reported errors, but the car just wouldn’t have it.
It’s now been recovered to our local dealers and I await a phone call today to see when they can look at it. I picked up a hire car this morning, arranged by MG Assist, but that is only for four days, so I will have to see how the dealer responds. I’m disappointed, but these things happen, the car is low mileage 21 months old.

Not good news, Dealer can’t look at until December, MG UK unsympathetic, no hire car until dealer has diagnosed fault and given time frame, and if it meets MGs criteria of parts outstanding or lengthy technical case, then dealer can apply to MG to authorise a hire car.

It’s not the dealers fault they are busy, but MG could be a lot more sympathetic in dealing with this sort of situation.
 
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Might be better to get your posts in their own thread rather than bringing back this 2 year old one that isn't the exact issue you have.
Maybe the mods can do the business...
[ Moderator: Done. ]
 
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The HV battery shutoff warning is a bit confusing. It's natural to interpret this as a hardware fault, and it may be that, but often it's trying to say "you're doing something that requires the car to be in ready mode (HV battery connected), but you're not currently in ready mode".

Have you put your foot firmly on the brake pedal for a second or so before pressing start? What can happen is that as we become familiar with the car, we do the startup procedure quicker and quicker without thinking about it, and eventually the start button is pressed a fraction of a second before the brake pedal, and the car goes into one of the accessory modes where the HV battery is still disconnected. It happened to me too. I simply adjusted my startuo habit a little, and now it never happens.

My apologies if this has been tried and failed. If not, it would be good if the AA people knew this common problem and suggested the above remedy first thing.
 
no hire car until dealer has diagnosed fault and given time frame, and if it meets MGs criteria of parts outstanding or lengthy technical case, then dealer can apply to MG to authorise a hire car.
We were in a similar situation with our Gen1 ZS EV a few years ago.
Car was recovered to our local dealers on a Saturday morning when the handbrake on the O/S/R locked fully on !.
AA guy was able to temporarily manually release it and was then able to drive the short trip to the garage.
The car was left outside of the workshop door and it was taken in by midday and the problem was diagnosed quickly and parts placed on order.
Unfortunately both parts required were on “Back Order” 👎.
The dealer had contacted the MG after sales team and they authorised the use of a hire car the same day.
We received the car on the Monday and had it for 2 days short of a month !.
The day the second part hit the dealers, MG instructed the dealer to make time to install the parts !.
As they intended to have the hire car collected on the same day as the work was completed.
I picked up the car at 4.00pm and by 6.00pm the hire car was gone !.
The bill for the car hire must have been expensive, when considering that both of the replacement parts, totalled less than £300.00 plus 1 or 2 hours of labour only.
Costly car hire charges are a direct result of the slow supply of replacement parts that are not held in U.K. stock.
 
The HV battery shutoff warning is a bit confusing. It's natural to interpret this as a hardware fault, and it may be that, but often it's trying to say "you're doing something that requires the car to be in ready mode (HV battery connected), but you're not currently in ready mode".

Have you put your foot firmly on the brake pedal for a second or so before pressing start? What can happen is that as we become familiar with the car, we do the startup procedure quicker and quicker without thinking about it, and eventually the start button is pressed a fraction of a second before the brake pedal, and the car goes into one of the accessory modes where the HV battery is still disconnected. It happened to me too. I simply adjusted my startuo habit a little, and now it never happens.

My apologies if this has been tried and failed. If not, it would be good if the AA people knew this common problem and suggested the above remedy first thing.

Yes, I am aware of the "foot firmly on brake" before doing anything syndrome, having once or twice early in my ownership of the car caused this problem, but simply switching off and restarting cured the fault. Both the AA men who came out were well aware of the issue as well, and also tried the battery disconnect etc

We were in a similar situation with our Gen1 ZS EV a few years ago.
Car was recovered to our local dealers on a Saturday morning when the handbrake on the O/S/R locked fully on !.
AA guy was able to temporarily manually release it and was then able to drive the short trip to the garage.
The car was left outside of the workshop door and it was taken in by midday and the problem was diagnosed quickly and parts placed on order.
Unfortunately both parts required were on “Back Order” 👎.
The dealer had contacted the MG after sales team and they authorised the use of a hire car the same day.
We received the car on the Monday and had it for 2 days short of a month !.
The day the second part hit the dealers, MG instructed the dealer to make time to install the parts !.
As they intended to have the hire car collected on the same day as the work was completed.
I picked up the car at 4.00pm and by 6.00pm the hire car was gone !.
The bill for the car hire must have been expensive, when considering that both of the replacement parts, totalled less than £300.00 plus 1 or 2 hours of labour only.
Costly car hire charges are a direct result of the slow supply of replacement parts that are not held in U.K. stock.

I went to the dealers today, and had all bad news, they can't even look at it until early December! I did persuade the girl on the desk to have a word with the workshop, but she returned and said they had had a quick look when it came in to determine the nature of the fault, but couldn't get it in to the workshop any earlier.

I also emailed MG UK customer service, who replied with a wordy email that basically said,"Sorry, but nothing we can do until the dealer determines how long repairs will take, your problem until then)
 
I had the same situation.

Firstly no dealer would accept the car from the AA as they were all too busy

When I found one he said it would be at least a week to look at it

Over two to weeks back and forth with MG for support ( mg only uses email and not phone calls!)

I got the garage to pressurise MG and I had a hire car for 6weeks

But I u derstand your frustrations

Lovely car but worst after sales service ever
 
I don't know if your problem is the same as mine.

I have been in a 'HV battery shut off' problem twice. In both situations I found that the brake pedal had gone hard and there was limited travel. To get the car started again I pushed down really hard on the brake pedal with my foot and then pressed start. And when I say really hard I mean maximum foot pressure I can exert on the pedal.

It seems when the brake pedal goes hard there is not enough travel in the pedal under normal foot pressure to engage the switch that gives the car the green light to start up the battery. Must be an undocumented design feature.
 
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I had the same situation.

Firstly no dealer would accept the car from the AA as they were all too busy

When I found one he said it would be at least a week to look at it

Over two to weeks back and forth with MG for support ( mg only uses email and not phone calls!)

I got the garage to pressurise MG and I had a hire car for 6weeks

But I u derstand your frustrations

Lovely car but worst after sales service ever
I have had quite a long email conversation with MG UK, to the point where they "escalated" my case to "head office" after thanking me for my "continued correspondence" ;) They eventually offered me £100 towards car hire as a "gesture". I declined, saying that amounted to 3 days hire at most, and I was looking at 4 weeks before the dealer could even look at it.

Without being insulting I told them how poor I thought their idea of customer service was, and to be assured that I would not hesitate to relate my experience.

All gone quiet now, I guess that is "case closed" as far as they are concerned.

I don't know if your problem is the same as mine.

I have been in a 'HV battery shut off' problem twice. In both situations I found that the brake pedal had gone hard and there was limited travel. To get the car started again I pushed down really hard on the brake pedal with my foot and then pressed start. And when I say really hard I mean maximum foot pressure I can exert on the pedal.

It seems when the brake pedal goes hard there is not enough travel in the pedal under normal foot pressure to engage the switch that gives the car the green light to start up the battery. Must be an undocumented design feature.
That's interesting. I did notice the pedal go hard at one time. The AA man pushed the pedal very hard though, so may have been aware of this syndrome. He actually said he was pressing the brake hard as he did it.
 
Just a bit of an update. The dealer is now telling me my car might have to go to an "HV Center" as the battery may have to come out. I'm getting very little information, and I rather suspect they actually don't have EV trained staff, as they appear not to have diagnosed it, it certainly hasn't moved according to the app.

I'm at a bit of a loss as to how to proceed now, the car broke down (failed to start) on 1st November and was recovered to the dealers the next day, and that's it. MG UK won't supply a courtesy car until the dealer tells them the diagnosis and how long to get parts etc, and the dealer is saying they might have to send it somewhere else!

Contact from the dealer is nil so far, and every time I ring, the person I need to speak to isn't there, and will ring back - but of course they don't...
 
It sounds like they intend to ship the car to Longbridge then ?.
I believe MG have a EV Tech Centre there.
I've no idea, they are saying they need a "Level 4 Technician" which they don't have. I get the impression they've not had to deal with this problem before. Under a bit of pressure from me, they have now applied to MGUK for a courtesy car.
 
I've just been reading up on Level 4 EV training. I think maybe I should apply, I have City & Guilds Pt 1&2 Motor Vehicle Technician certificates, and worked for 20 years in the Trade as a Vehicle Electrical and Diesel injection engineer.

The only problem is that it was over 50 years ago, and they probably don't want a 75 year old Boomer let loose in their workshop! :LOL:
 
A further update.

This is the response from MG UK to my email asking which Kent dealers had the necessary trained staff to repair my car, and if there was an HV center for MG traction battery repairs.

“Good afternoon
Thank you for the response back.

Unfortunately I am not able to see a list of what dealerships may have level 4 technicians.
I wouldn’t also be able to know if theres a central HV battery centre in the UK either.”


Absolutely useless. MG UK is basically a call centre, with no idea of what is going on out in the real world.

So where do I go from here? 😳

The dealer doesn’t know what to do, they just fob me off when I ring or email (they never ring me).

I’m looking into what legal action I can take now.
 
Hi all, I had this issue and was told to turn the vehicle off and then walk away from the car so that the car key no longer has connection to the car. Only then does the cars computer system properly shutdown and reboots when you turn the car back on. AA suggested being away from the car for approx. 10 mins however it may work in less time.
 
My car has been repaired at last!

Battery removed and parts replaced (the girl on the desk isn’t techy!) and all is well again, so nice to have it back after 3 months off the road.

I’ll see if I can get more info on what was replaced, and post it up for interests sake.
 
My car has been repaired at last!

Battery removed and parts replaced (the girl on the desk isn’t techy!) and all is well again, so nice to have it back after 3 months off the road.

I’ll see if I can get more info on what was replaced, and post it up for interests sake.
It will be interesting if you can get any more info.
I assume the work was not carried out by a local dealer ?.
Was the car transported back to Longbridge by any chance 🤷🏻.
 
I’ve been on to the service manager for a bit more detail, and it was the EDM (Electronic Data Monitor) that had failed, and there was very slight thermal damage to the CMU (Cell Monitoring Unit) so this was replaced as a precaution.

It was a long haul to get this repair done, but it’s difficult to fault the dealer, they didn’t have a Level 4 tech required to open the battery and work on it. This is mostly due to MG who didn’t make the courses available until the end of last year. The dealer has acted and will now have four level 4 techs by the end of February, and will be a certified battery centre, so they have really been positive.

The work was carried out at the local dealers by an MG UK technician. The Service Manager told me that initially repairs had to go to Lomgbridge, then they had the remote team, then battery centres, and lastly made the training available to all at the end of last year. The actual repair didn’t appear to take long, I was monitoring vehicle starts on my iSmart app, and it looks like the battery was removed, opened and diagnosed in one morning, I was told parts had been ordered, which took a couple of weeks and the car was back together in another morning.

The dealer had tried getting my car sent to another dealers with Level 4 tech, or a battery centre, without success, and I drew a complete blank with MG UK, they just laid it all at the dealers door to resolve.

It’s not been a good experience to have my car off the road for three months before it could be repaired, but as I said, I’m reluctant to blame the dealer, this wasn’t even a car they sold!

I take comfort that should something similar happen again I now have a battery centre locally, and any repairs should take a fraction of the time this one did!
 
Good to hear the update, thanks. Did you have a loan vehicle for the whole 3 months?
 
Good to hear the update, thanks. Did you have a loan vehicle for the whole 3 months?

I didn't have a loan vehicle at all, that was a sore point in all this. I had a courtesy car for 4 days, supplied through MG assist (who were brilliant) and the dealer couldn't look at the car for the first month, but MG UK steadfastly refused to supply one, saying it was the dealers responsibility, unless there was a long hold up for parts or technical reasons, whereupon the dealer could approach MG UK to fund a car. I had quite a long email exchange with MG UK and they were very dismissive, applying the well known "Delay, Deny, Defend" tactics. It has put me right off the Marque, which is a pity, as I like the car.

The dealer maintained throughout that they didn't have a car available, whereas I suspect that they were reluctant to pay out anything that they couldn't reclaim from MG UK on a warranty repair, especially as they hadn't sold me the car in the first place. The dealer I bought it from closed (or had closed by MG!) both their Kent MG franchises before my car was a year old!
 
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