MG5 Trophy Breakdown – A Worrying Experience

[stourlad50]

Hi all,

Long-time reader here! I’ve been driving an MG5 Trophy as a company car for just over 18 months now. Overall, I’ve really enjoyed it – it’s comfortable, drives well, and has been totally reliable… until a few weeks ago when it completely died on me. Buckle up – it’s a bit of a story!

We had a family holiday planned and needed to drive from Wolverhampton to Birmingham Airport, not a huge journey. I got the annual service done 5 days beforehand – no issues flagged at all.

Fast forward to 4 AM on a windy, snowy Friday morning (22nd November). We’re cruising along the M42 at 70mph, just a few miles from the airport, when the HV battery warning light suddenly pops on. I figured I’d push on since we were so close. Big mistake. Within 5 minutes, all sorts of warning lights started flashing, and then… everything went dead. Like someone had pulled the plug.

We were just one junction away, on a bridge over the M6 Toll. Thankfully, it was quiet that early, so I managed to roll onto the hard shoulder. But then things got worse:

• The electric handbrake wouldn’t engage, so I had to keep my foot on the brake to stop the car rolling.
• The entire electrical system was dead, meaning no hazard lights either.
• Sitting in a powerless car, in the snow, on a bridge over the motorway, at 4 AM… not ideal.

I rang the AA straight away, explained the situation, and while the operator was sympathetic, they told me it’d be at least 3 hours before anyone arrived (our flight was in 4.5 hours – stress levels rising!).

About 30 minutes later, a traffic cop knocked on the window. Top guy – he gave us foil blankets to keep warm and put some cones out behind the car. He also advised us to get out, but with no handbrake, that wasn’t happening. He stayed parked behind us with his lights on until recovery arrived, which was a massive relief.

Thankfully, we were in a “Free Motorway Recovery” zone, so the recovery truck beat the AA to the scene. The driver dropped us at the airport (lifesaver!), but it wasn’t smooth – the boot wouldn’t open, so I had to drag all the suitcases over the back seats. I let my boss know, left the car with recovery, and went on holiday.

Since then (this all happened on 22nd November), I’ve been driving a hire car provided by MG. The part they think failed – the DCDC controller (or CCU?) – is on back order, and they don’t even have a delivery date yet. My hire car is booked until the end of December, so it’s anyone’s guess how long this will drag on.

Now I’m left wondering – has anyone else had something this catastrophic happen with their MG5? I’ve looked around the forums but can’t find anything quite as severe.

I’ll admit, this whole experience has shaken my confidence in the car, especially for longer trips. If this had happened in busier traffic, it could’ve been far worse.

Keen to hear if anyone’s had similar issues, or any advice on what I should do once the car’s “fixed.”

Thanks for reading – and sorry for the long post!

 

[Alb]

Glad you still made the holiday!
Having the DCDC Controller fail is akin to an Alternator failure on an ICE car. The lesson seems to be that the initial warning should be addressed immediately by pulling over as soon as safe. You probably could have made the 12V functional again (at least temporarily) if you had a 12V battery booster. Lots of owners carry these now as battery failure is relatively common on these cars.
The rest is down to MG's supply chain which we all know is routinely found to be weak.

 

[salty]

 

[stourlad50]

Glad you still made the holiday!
Having the DCDC Controller fail is akin to an Alternator failure on an ICE car. The lesson seems to be that the initial warning should be addressed immediately by pulling over as soon as safe. You probably could have made the 12V functional again (at least temporarily) if you had a 12V battery booster. Lots of owners carry these now as battery failure is relatively common on these cars.
The rest is down to MG's supply chain which we all know is routinely found to be weak.

Thanks Alb, I'll certainly make sure I've got one in the back of the car in future!! (As soon as I can get it back)

 

[Amun]

You probably could have made the 12V functional again (at least temporarily) if you had a 12V battery booster. Lots of owners carry these now as battery failure is relatively common on these cars.

Does anyone have specific recommendations for one of these?

 

[Alb]

There's a few existing threads on this like:

Jump Starter pack at a reasonable price

Saw this today. Thought it might be useful. ASPERX 5-in-1 Jump Starter Power Pack, 3000A w/voucher Sold by JIAHONGJING store / FBA | hotukdeals

www.mgevs.com

I bought a Gooloo from Amazon based on price last year and it still seems to be OK. If I were buying again I'd be tempted to go for something like this:

https://www.amazon.co.uk/Starter-Compressor-Battery-20000mAh-Emergency/dp/B0CTMGMRVD

Seems like a neat idea to incorporate dual functionality into one box.

 

[Fintious maximus]

My 24 plate had a hiccup a couple of weeks ago - stopped to charge on way home and at 85% or so I unplugged and then when I pressed the start button the HV battery warning came on and it wouldn’t start. Took me a while to work out that if I stood outside and locked it for 5 minutes it seemed to reset something and it worked. Wouldn’t have fancied your issue

 

[dragon2611]

My 24 plate had a hiccup a couple of weeks ago - stopped to charge on way home and at 85% or so I unplugged and then when I pressed the start button the HV battery warning came on and it wouldn’t start. Took me a while to work out that if I stood outside and locked it for 5 minutes it seemed to reset something and it worked. Wouldn’t have fancied your issue

I've had that happen a few times on my pre-face lift although it's usually at the start of charging if it sees something about the charger/cable it doesn't like.

Either locking it and wait 5-10mins or disconnect the 12v battery usually solves it.
Did try a code clear from a wi-fi ELM327 and carscanner but that didn't work

 

[5teep]

My 24 plate had a hiccup a couple of weeks ago - stopped to charge on way home and at 85% or so I unplugged and then when I pressed the start button the HV battery warning came on and it wouldn’t start. Took me a while to work out that if I stood outside and locked it for 5 minutes it seemed to reset something and it worked. Wouldn’t have fancied your issue

Could just be that you didn't give the car enough time to boot up before trying to select gear etc. I get the same sometimes because I'm impatient.

 

[kla456]

My 22plate stopped on the motorway with whole family on way home from airport. That was in August. MG refused their own dealership's report because the dealer did not have a level 3 certified technician. Only one level 3 training available in Scotland (they told me) and fully booked. I went to the dealership yesterday. They said my car is next but one for assessment - they have been saying that for weeks. They won't sell me a new one because the sales side can't be sure when it will be fixed for trading in. No hire car because MG still didn't get the level 3 technician report.

 

[andymcdoodle]

I've had that happen a few times on my pre-face lift although it's usually at the start of charging if it sees something about the charger/cable it doesn't like.

Either locking it and wait 5-10mins or disconnect the 12v battery usually solves it.
Did try a code clear from a wi-fi ELM327 and carscanner but that didn't work

Hi
Could you tell me where the 12v battry is?
When I lift bonnet all I see is a plastic cover??

 

[kevin ellard]

Hi
Could you tell me where the 12v battry is?
When I lift bonnet all I see is a plastic cover??

Right hand side as you are looking at it. You should be able to see the connectors.

 

[andymcdoodle]

Thankyou will have a look next time I'm under bonnet

 

[dragon2611]

Hi
Could you tell me where the 12v battry is?
When I lift bonnet all I see is a plastic cover??

Under the plastic cover, on my pre-facelift there's a smaller panel that comes off separately to save you from having to remove the entire plastic cover.

I think that standard on the long range versions not sure if it was on the early short range cars.

 

[Alb]

Same on the SR.
This is what it looks like under the cover on my car: