Red 'Check HV Battery'

[TBaLLS46]

Hi All,

Ive searched through the MGEVs forum and i cant really find a problem that matches our cars. Ill list our ongoing story in the hope it might help somebody else.

• We have had the car since the 5th of October 22.
• On the 6th of October, i managed to get a HV battery fault while plugging the car in. I waited 3 mins and everything reset and we were able to drive. I happened to share this with the dealer, via email.
• Beginning of November my wife complains of new warning messages. She says something along the lines of 'faulty HV' and a red image (see photo for ref)
• 16th November 22, Car goes into limp mode. Car is recovered and taken back to MG Richmond. had to mess around with hire cars and courtesy cars, very inconvenient.
• The car has spent two weeks with the dealer. They cant find any record of HV battery issues in the diagnosis, but identify problems with some wiring? Claim its fixed, return the car.
• 2nd December 22, less than 5 miles of driving from the dealer, 'Check HV Battery' message and red logo appear. After 10 seconds they go. Dealership has now closed.
• Call the dealer Saturday at opening, the courtesy car we returned is now out? wtf when, you haven't been open. they were not willing to swap the car again.
• Drove around all weekend, with more occasional 'Check HV battery' warnings.

Ill continue to add as i get more information, its still a live issue. My wife needs to use the car tomorrow, im a bit at a loss what to do. Im looking at the advice on the motor ombudsman website. Not sure if i should keep letting the dealer keep trying to fix it, or if i should be asking for a replacement. Im not keen on asking for a refund as I predict i will lose out, i.e. no grant, worse finance and inflated prices.
If anybody has any good advice, please share.

Thanks!

UPDATE (09/12/22)

Have spoken to MG Richmond Southampton who have had our car for 3 days now.
We have been told

• the Technicians raised the issue with MG HQ.
• MG HQ have said its a know issue. Looking at the similarity in symptoms described by people in this post Im not surprised.
• The issue is a software issue and it is perfectly safe to drive, with the 'Check HV battery' warning. I do question this, if its going into limp mode, allthough they did 'fix' some loose wiring on our car, and it has not gone into limp mode since the first visit to the garage.
• MG will release an update and they will contact us to update our car when its ready.

I really hope that's it. hopefully we can pick it up today and it wont go to limp mode. Need to drive to europe for xmas.
This post is just for the issues on my car. Please read the main post here: Mystery Faults

 

[TBaLLS46]

Ive spotted this post.

Mystery Faults

Hey Barry22 sorry to hear that! (But a small part of me is glad I'm not alone in this) So turns out they didn't swap the battery, they swapped the BMS which it turns out involves removing the whole battery tray. What a lush piece of design eh! Either way, they also found a bent pin on the VMU...

www.mgevs.com

it has other with the same issue.

 

[dragon2611]

Same issue as Mine.

Is yours a 72 plate?, there seems to have a bunch of prefacelift models about being sold off, probably due to the new facelift model coming out. I did wonder if they'd been sitting somewhere for a while.

Edit: I see my post from yesterday only just went live (probably due to waiting for account approval)

 

[TBaLLS46]

Same issue as Mine.

Is yours a 72 plate?, there seems to have a bunch of prefacelift models about being sold off, probably due to the new facelift model coming out. I did wonder if they'd been sitting somewhere for a while.

Edit: I see my post from yesterday only just went live (probably due to waiting for account approval)

Yes its a 72 plate, but ordered in February. I had a fear that although it would be shipped reasonably quickly once complete, that some parts may have been in storage waiting to complete assembly.

 

[svacher]

My wife and are going back to the dealer today to pick up her MG5. She has been having the same issues with the ‘Check HV battery’ warning popping up then going away, apart from the last time when the car went into turtle mode in the outside lane of the motorway.
She managed to get it going again after getting to the hard shoulder, she drove it straight to the dealer. They have had it for a week with ‘no fault found’.
When it went in the technician cleared the error log because they were “old faults”, she has only had the car since September.
I'm with you, I’m very unhappy about her driving around a car that at any moment could lose all power.

 

[TBaLLS46]

My wife and are going back to the dealer today to pick up her MG5. She has been having the same issues with the ‘Check HV battery’ warning popping up then going away, apart from the last time when the car went into turtle mode in the outside lane of the motorway.
She managed to get it going again after getting to the hard shoulder, she drove it straight to the dealer. They have had it for a week with ‘no fault found’.
When it went in the technician cleared the error log because they were “old faults”, she has only had the car since September.
I'm with you, I’m very unhappy about her driving around a car that at any moment could lose all power.

Hi svacher, the main post on this topic is here Mystery Faults
A lot of people have exactly the same issue. You should expect a response from the dealer along the line of "mg are aware, it's a known issue, it's safe to drive, it's just a software issue and mg will contact you when the update is ready."

As for turtle mode. The first time it happened my wife said the car was warning her to pull over. It went back to the dealer where they "fixed"some loose wiring and that hasn't happened since.

Yesterday the car went into turtle mode whilst I was driving on the motorway. No warnings to pull over, just slowed to about 55. I kept driving for a while because there was no safe place to pull over. Before I could pull over, the fault had cleared and I was off again. So although it's not great, turtle mode shouldn't cause you to stop unpredictability. I know that's not reassuring, once confidence has been lost, it can be very hard to regain.

 

[dragon2611]

Yesterday the car went into turtle mode whilst I was driving on the motorway. No warnings to pull over, just slowed to about 55. I kept driving for a while because there was no safe place to pull over. Before I could pull over, the fault had cleared and I was off again. So although it's not great, turtle mode shouldn't cause you to stop unpredictability. I know that's not reassuring, once confidence has been lost, it can be very hard to regain.

It's an absolute pain however to pull away if you are stopped, it would certainly cause issues on a non traffic light controlled junction.etc, and usually if it happens when you are waiting to pull out somewhere you'd have to move otherwise you'd be blocking the junction/roundabout entrance.etc

 

[HappyExistence]

I have been in touch with BBC Watchdog re this problem , suggest you all do the same , maybe if enough of us email them we can get some reputational leverage from the BBC.

Did over 400 miles this weekend , happy to report no issues , and 3.5 miles per kw which given the sub zero temperatures I was very pleased. The update appears to have worked