MG5 Mystery Faults

[Squidder]

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 main loom connector and fixed that, positing that this perhaps was the cause of all our woes, and gave me the car back Fri 18th November. 5 instances of limiting power and numerous HV battery errors I took the car back to them Monday 21st morning. Also after this I discovered the the range estimate no longer changed when changing driving modes!

This is still ongoing. I've owned the car (as of Friday just gone) 73 days and of those it has spent almost half in the dealership.

To those who said to return the car, I'm too invested now emotionally, I have to find out what is causing this. Plus so when people like myself and Barry search the internet in the future, they may not have to spend 30 odd days of diagnostics!

 

[barry22]

I thought I was the only one also… I’ve had mine at MG and they didn’t have a clue.
All the said was that they have to wait to hear back from the main MG garage.

Mine seems to be getting worse and happening on a daily basis. Goes into Limp mode - turtle mode daily. Happens at least twice a day and check HV batter is on and off throughout the day.

I usually pull over, turn off and wait a few mins. Doesn’t always work but sometimes it does.

It’s really starting to annoy me now.. keep me posted on what happens please and like wise I will with you.

 

[TBaLLS46]

Crumbs, just made my own post. Basically the same sort of issue. Its only gone into low power mode once, when my wife was driving.

1. took delivery 05/10/22
2. error with HV battery when plugging into the charger at home 06/10/22
3. a number of 'Check HV Battery' messages and a low power mode.
4. returned to the dealer, they claim not to find any 'Check HV Battery' faults in the log and 'fix' some loose wiring and return the car. it took two weeks.
5. less than 5 miles after picking the car up 'Check HV Battery' warning appear.
6. now dont have a courtesy car to swap to. dealer closed for the weekend, we are just driving and hoping its safe.

Thanks, ill keep you guys informed. Im going to ask for a replacement car.

 

[barry22]

Hopefully they will get to the bottom of this issue as it’s happening more often with other cars now.

Yes please keep us updated. Mine is due to go back to MG dealer in a week and they are giving me a courtesy car, they want to keep the car for 3 days they’ve said. I’ll be straight on here to update you guys.

I’m still having the issue daily with mine. Really frustrating!!!

This is how mine goes…..
2/12/22
Dry/sunny 7 degrees
Check hv battery 100%
Check hv battery 97%
Check hv battery 88%
Check hv battery 84%
Check hv battery 83%
Check hv battery 79%
Check hv battery 78%
Check hv battery 75%
Limp mode 75%
Check hv battery 74%
Check hv battery 61%
Check hv battery 45%

3/12/22
Sunny 5 degrees
Check hv battery 91%
Check hv battery 85%
Check hv battery 78%
Check hv battery 76%
Check hv battery 66%
Limp mode 66%
Check hv battery 64%
Check hv battery51%
Limp mode 50%
Check hv battery 45%
Check hv battery 33%

My list goes on unfortunately.

 

[TBaLLS46]

Hopefully they will get to the bottom of this issue as it’s happening more often with other cars now.

Yes please keep us updated. Mine is due to go back to MG dealer in a week and they are giving me a courtesy car, they want to keep the car for 3 days they’ve said. I’ll be straight on here to update you guys.

I’m still having the issue daily with mine. Really frustrating!!!

This is how mine goes…..
2/12/22
Dry/sunny 7 degrees
Check hv battery 100%
Check hv battery 97%
Check hv battery 88%
Check hv battery 84%
Check hv battery 83%
Check hv battery 79%
Check hv battery 78%
Check hv battery 75%
Limp mode 75%
Check hv battery 74%
Check hv battery 61%
Check hv battery 45%

3/12/22
Sunny 5 degrees
Check hv battery 91%
Check hv battery 85%
Check hv battery 78%
Check hv battery 76%
Check hv battery 66%
Limp mode 66%
Check hv battery 64%
Check hv battery51%
Limp mode 50%
Check hv battery 45%
Check hv battery 33%

My list goes on unfortunately.

Where are you getting that detailed list from? or just making a note yourself?

 

[barry22]

Just doing it all myself on my phone and taking pics when it happens.

 

[Squidder]

Crumbs, just made my own post. Basically the same sort of issue. Its only gone into low power mode once, when my wife was driving.

1. took delivery 05/10/22
2. error with HV battery when plugging into the charger at home 06/10/22
3. a number of 'Check HV Battery' messages and a low power mode.
4. returned to the dealer, they claim not to find any 'Check HV Battery' faults in the log and 'fix' some loose wiring and return the car. it took two weeks.
5. less than 5 miles after picking the car up 'Check HV Battery' warning appear.
6. now dont have a courtesy car to swap to. dealer closed for the weekend, we are just driving and hoping its safe.

Thanks, ill keep you guys informed. Im going to ask for a replacement car.

Sorry to hear that TBalls.
Interesting to hear that this is more common than we first thought. I've also heard via the garage I bought the car from (NOT an MG dealership) that they've heard through their network of a couple of instances of this happening also.
I have asked the MG dealership my car is in with about replacing the vehicle but it seems that as I bought a new car through an independent garage I'm in a weaker bargaining position
Same as Barry22 I also was logging it whenever it happened. (of course getting my passenger to photograph the dashboard!)

Hope you both get some resolution.

 

[Squidder]

Oh I also made a complaint to MG Customer Services saying this was a safety issue as the car can go into limp mode with no warning (including when I was on the motorway) and got brushed off in the first instance, made the same complaint again after getting the car back the most recent time and thankfully got a better response. Maybe worth getting anyone we know to prod MG Customer Services as well as MG technical/ warranty support

 

[dragon2611]

Just picked up a new MG5 LR (Pre facelift one) today and am having exactly the same issues described here, including going into turtle twice.

Did it once within 10miles of the dealer so turned around took it back where they cleared a fault code.

Had the check HV battery pop up a few times but this evening it turtled just as I was pulling onto a roundabount (thankfully not busy).

Will need to call them tommrrow or Monday (Service not open Sundays) and see what they want to do about it. It's a 200 mile round trip to that dealer so will be interesting to see what they want to do, not sure if the more local ones will be interested as they didn't sell the car.

 

[Alb]

A local dealer should be happy to work with your car.

 

[dragon2611]

A local dealer should be happy to work with your car.

At the moment I'm going to see what happens with the one who sold it to me, as ideally i'd like them to make the arrangements rather than me having to.

I know when I had a MG3 a few years ago with a gearbox problem one of the local ones claimed to be so backlogged they weren't interested, one of the others did take a look, although that was the one I recently cancelled an MG4 order with to get the 5 (as they still couldn't confirm an estimated date even though I was getting to the end of the 16week or so window they kept quoting.)


I don't seem to be having much luck with MGs,

MG3 couple years back had issues with 5th gear
MG4 demo car was throwing up TPMS errors when I test drove it.
MG5 check HV battery.

 

[TBaLLS46]

Just picked up a new MG5 LR (Pre facelift one) today and am having exactly the same issues described here, including going into turtle twice.

Did it once within 10miles of the dealer so turned around took it back where they cleared a fault code.

Had the check HV battery pop up a few times but this evening it turtled just as I was pulling onto a roundabount (thankfully not busy).

Will need to call them tommrrow or Monday (Service not open Sundays) and see what they want to do about it. It's a 200 mile round trip to that dealer so will be interesting to see what they want to do, not sure if the more local ones will be interested as they didn't sell the car.

If its within 30 days of purchase you can return it and ask for a refund/replacement. Check the motor ombudsman website.

 

[dragon2611]

If its within 30 days of purchase you can return it and ask for a refund/replacement. Check the motor ombudsman website.

I'll give them an opportunity to put it right first.

Edit: The Dealer that I bought the car from have made arrangements with a local MG dealer for them to have a look at the car. I should be taking it tomorrow

 

[SteBrod]

Had mine a week and the same problem.
Check HV battery warning pops up on nearly every trip and then disappears.
Went Into limp home on one trip which cleared after a couple of miles.
Doesn’t sound like it’s an easy fix

 

[dragon2611]

Has anyone noticed any correlation between slowing down (Kers) and the check HV battery message

 

[TBaLLS46]

Has anyone noticed any correlation between slowing down (Kers) and the check HV battery message

not any thing specific. My wife is always keeping her eye on the 12v battery gauge. apparently our car never goes to 14v, but the courtesy car was almost always 14.1 - 14.2v. The information ive had from the garage when they 'repaired' it was that there was some 12v faults on the system.
We had the stereo system restart one occasion, and that seemed to trigger the 'check HV battery' message.
We also normally drive with the car in eco + kers 3. not sure if its connected, but that shouldn't cause a problem.
So far, we havent been able to repeatably cause the fault, I've tried.

 

[dragon2611]

Mines been at 14.1/14.2v so doubt it's that,

Currently sitting in a local MG dealer whilst they look at the car, I think they want to update some software so not sure if there's a newer software build about, I know the dealer that sold it said they had already updated to the software versions specified in their Pre delivery inspection guidance.

 

[TBaLLS46]

Mines been at 14.1/14.2v so doubt it's that,

Currently sitting in a local MG dealer whilst they look at the car, I think they want to update some software so not sure if there's a newer software build about, I know the dealer that sold it said they had already updated to the software versions specified in their Pre delivery inspection guidance.

Our delivery pickup 05/10/22 was delayed so that they could update the software. so it should all be upto date.

 

[dragon2611]

No Idea on that one, just reporting what they said to me just now. Maybe there's another newer version, maybe they're actually downgrading it to an older version.,

 

[dragon2611]

Well they didn't seem to like something about the Software versions/state so apparently they're going to replace the VCU (Vehicle control unit), need to drop it back in Friday morning and apparently they'll have a courtesy car available.