My MG4 Trophy has stopped charging after returning from its 2 year service

[les37b]

Ok, quick update.

Tried a different granny charger with the same result. Tried a DC fast charge and that was ok so booked in for investigation the day after returning from holiday.

On the morning, I decided just because and try the charger again. It lasted 15 minutes (at peak rates) which it hadn’t managed before, so figured it must be ok now and cancelled the booking.

Typical, I tried charging again in off peak rates and it failed in just 1 minute.

So rebooked in and yes as had been suggested it was a failed CCU which I got replaced under warranty. Hopefully it’s now fixed!

I asked what the cost would have been and was told about £2000.

Now obviously it was covered, but that’s a scary sum of money for a chip in a car for which they could offer no explanation of why it went wrong.

 

[Rolfe]

Yes, the main symptom with this has been cars charging for only a short time then cutting out. In the early days dealers were telling owners that the car was charging fine, because they'd only left it for 15 minutes or so. People were having to go back and tell them to leave it overnight and see what happened.

As far as I remember, many people noticed the cars charging for shorter and shorter times and then giving up.

Just as well we have that 7-year warranty if things are going to take this long to show up.

 

[Coulomb]

I asked what the cost would have been and was told about £2000.

Now obviously it was covered, but that’s a scary sum of money for a chip in a car

It's more than just a chip, it's an entire power electronics module with case, PCB, many parts including high power devices, water cooling, connectors, etc. Hopefully the parts in there are "automotive qualified", which makes them more expensive than consumer grade parts. Then there are taxes, transportation, warehousing and handling costs, and so on.

The equivalent part for a Mitsubishi iMiev, at half the power, has been quoted as US$4000 (before the recent high inflation), so £2000 for a 7kW charger and >150A DC-DC is actually not completely unreasonable. However, it does make them candidates for board level repair, especially if some common failure modes are known.

 

[les37b]

OK further update.

Got the car back with the CCU repair completed. It was on 100% when returned. Ive done about 80 miles since then. I was on 49% and gave it a charge back up to 79%. All seemed to be working ok. Took the car out, did a few miles and left it yesterday evening on 76%.

Went out this morning and found the far was as dead as a dodo. Obviously it could be the key fob battery dead, but neither worked. I called the MG Dealer - Ancaster MG in Bromley and they simply said "bring it in and well do a diagnostics on it. The fact it had dome less than 300 miles since they did a full service and a CCU warranty repair counted for nothing. I explained I couldnt even open the door. I was aware of the methods to use the key lock, but couldnt work out how to flip the door handle part to reveal the lock. Nope - sorry, ring up the AA. I rang MG customer care. They said the same. Ring the AA. I said surely there must be someone there able to help getting into the car. "Send us a photo of the hole you are inserting the key". I did and haven't heard a thing back. He said "try sliding it" - which is obviously not what you do.

I have finally got in. I was in the right direction - just concerned not to put pressure on it.

The car is dead. Pressing the pedal, nothing happens.

I have put about 20% charge in since getting it back and I really cant help thinking this car is a lemon.

Any ideas? What should I be doing or what the issue might be?

 

[Martinonline]

It sounds like your 12V battery is dead. You need to charge it to get the car to power up.

 

[OriginalBigAl]

Or , just check the connections are solid, could have been overlooked at the dealers?

 

[les37b]

It sounds like your 12V battery is dead. You need to charge it to get the car to power up.

I think that is what it is… all my fault.

Last night I was trying to get android auto to work… it was after midnight. I always have my lights on auto but they were so bright, I turned them off… or so I thought. I suspect I’d put them on sidelight. At least that makes complete sense.

How does the battery normally get a charge? Via a dynamo or similar? I have one of those uSB starters, but guess that’s not going to help. I have a Ctec stop start charger which I connected, but all it said was “checking”. On my way out so didn’t have time to keep it on and wasn’t chancing leaving as I’m not back for 10 hours.

Hopefully I won’t need to buy another 12V battery! Is it likely the cTec one will kick in to charge?

 

[Edd Beesley]

Part of the cars electronics is a step-down converter that takes the ~400 V battery and steps it down to 12V - this keeps all the 12V stuff powered while driving and charging, and keeps the 12V battery topped up. This may well be part of the CCU as well, so possible your 12V has been draining since repaired, or, as you say, perhaps you left the light on (I did that with my other car at the weekend, left the doors open for a few hours while cleaning it and that was enough to kill the 12V battery!)

 

[les37b]

Part of the cars electronics is a step-down converter that takes the ~400v battery and steps it down to 12V - this keeps all the 12v stuff powered while driving and charging, and keeps the 12v battery topped up. This may well be part of the CCU as well, so possible your 12v has been draining since repaired, or, as you say, perhaps you left the light on (I did that with my other car at the weekend, left the doors open for a few hours while cleaning it and that was enough to kill the 12v battery!)

When you say kill, do you mean that literally? New battery or did you manage to get some charge in it)

 

[Martinonline]

From reports on this forum the 12V battery recovers and in the problem was a glitch then it doesn't immediately or if ever re-occur.

Many of us have battery boosters to cover this situation and a 10mm spanner to release/tighten the battery connections.

My brush with this happened a year ago when the 12V battery dropped to an indicated 11.9V and a Low Voltage Battery Charging System failure warning showing. I tried the usual lock/unlock, drive around a bit, connect to AC and DC chargers (no changing). With the car at 11.5V I connected the battery and immediately there came the sound of operating relays and the problem was resolved. No problems since.

 

[Edd Beesley]

When you say kill, do you mean that literally? New battery or did you manage to get some charge in it)

I jumped it from my MG and it started fine, but the car/battery are 5 years old so I expect the 12V battery is now end of life!

 

[les37b]

Ok, another update!

The Ctec charger wouldn’t charge. It was left in “check” mode. The USB jumper didn’t work.

I managed to get some jump leads and connected to my wife’s ICE car and as someone said, I got the car back powering up. First time, I disconnected after about 30 seconds and it cut off again.

Second time, I left it with the ICE running for 10 mins, this time seemed ok. Even checked it would accept a charge and it did!

Here’s the But!

When it was doing system checks, pretty much every sensor “not available”. I’ve powered down completely and tried again. Same happens. The car will engage (I moved it a few feet) but not confident to take out with so much including brake stuff, not working.

Can this be reset somehow? Or is it yet another garage visit and £162 investigation charge?

 

[ReintjeWA]

Ok, another update!

The Ctec charger wouldn’t charge. It was left in “check” mode. The USB jumper didn’t work.

I managed to get some jump leads and connected to my wife’s ICE car and as someone said, I got the car back powering up. First time, I disconnected after about 30 seconds and it cut off again.

Second time, I left it with the ICE running for 10 mins, this time seemed ok. Even checked it would accept a charge and it did!

Here’s the But!

When it was doing system checks, pretty much every sensor “not available”. I’ve powered down completely and tried again. Same happens. The car will engage (I moved it a few feet) but not confident to take out with so much including brake stuff, not working.

Can this be reset somehow? Or is it yet another garage visit and £162 investigation charge?

Boosters often look for a sign of life from the 12V battery to prevent people hooking the leads up to the wrong terminals, there might be a override button on your booster that ignores this (at the risk of getting the polarity wrong) and lets you boost regardless.

I think it is normal for the car to think there are many faults after a hard reset (disconnected 12V battery) and they all seem to come back alive after a little bit, so I wouldn’t worry too much about those faults, unless they persist.

 

[les37b]

I uploaded a video showing the sensors



Ancaster just told me to call MG assist AA…

 

[Ian Key]

I uploaded a video showing the sensors



Ancaster just told me to call MG assist AA…

You need to remove the privacy settings from your video as we can't see it.

 

[siteguru]

All those features will reset in a few minutes ... the car is safe to drive.

PS - you'll need to reset the electric window controls and recentre the steering wheel. Check the Wiki - I think there's a link in there to tell you how to do these.

 

[Edd Beesley]

Ok, another update!

The Ctec charger wouldn’t charge. It was left in “check” mode. The USB jumper didn’t work.

I managed to get some jump leads and connected to my wife’s ICE car and as someone said, I got the car back powering up. First time, I disconnected after about 30 seconds and it cut off again.

Second time, I left it with the ICE running for 10 mins, this time seemed ok. Even checked it would accept a charge and it did!

Here’s the But!

When it was doing system checks, pretty much every sensor “not available”. I’ve powered down completely and tried again. Same happens. The car will engage (I moved it a few feet) but not confident to take out with so much including brake stuff, not working.

Can this be reset somehow? Or is it yet another garage visit and £162 investigation charge?

Sounds like your 12V was totally empty, and the fact it turned off when you disconnected the other car suggests a fault with your car as it should be able to maintain the 12V bus right away. I expect the car will die again and the 12V will be totally empty again as it's not being recharged by your car.

 

[MG Mile eater]

My MG4 came back from its 2 year service with a clean bill of health last week. The vehicle has 8,000 miles on the clock and I generally dont use it too much. Apart from a couple of short journeys of a few miles, I've not used it since, until today when I did a 60 mile trip leaving me at 123 miles and 49% left. So I decided to give it a charge on my trusty (and only used) method using my granny charger, and make use of my free solar to restore the charge just used. This has been a pretty routine activity since I've had it. I usually use a smart plug set to make use of my cheap Octopus cozy tariff, but today I just let it charge.

It started charging, but when I looked at my solar app, I could see it no longer was.

To cut a long story short, every attempt to charge, it would get the green light for about a minute then go out. I checked in case the car may have come back with some schedule in place (it had), but after removing that, then setting a schedule to come on for, then switched the car off so it's coming back on with a fresh start and nothing changes.

I had thought this evening it had starting working again. I'd set things with the smart plug and when I looked, I could see it was charging. Looked a short while later and it had stopped. Tried again and this time it had stopped after a minute as it had been doing. I left it and it started charging again. I expected a repeat (which I'd witnessed a couple of times), but now 15 minutes later and for the first time all day, I still have the green light....... but just gone out after 20 minutes...... and now no further green lights and now appears to have gone to sleep.

Any ideas? I spoke to the MG dealer who did the service, who told me prior to taking in, it had 2 recall updates. Today the dealer says "we didn't do any updates" and this fault that wasn't there before it was taken in, but is now on the first charge since I got back, is nothing to do with us and just a coincidence.

For the record, since I've had it, I've only ever used the granny charger - and not even got a clue how to use public EV chargers (e.g. do I need to register to use one?).

Go to a nearby charging hub try the type 2 , 7kW connection and then CCS charge. No need to register as all have to be contactless now.

 

[Martinonline]

I recommend you monitor your 12V battery voltage via the app to see that it is charging when the car is powered up (voltage > 14V usually) and when not powered up to see if the voltage is decreasing over time (you will probably have to do a few status refreshes to get a consistent report).

Also look out for this fault warning as shown in the image:

 

[siteguru]

As I recall, when DC (CCS2) charging (and maybe also when the car is off/locked, but may also be true if you're sitting in the car) the 12V battery is not recharged.