MG5 EV 2023 LR Rapid Charging, recovery & resolution guide

[Simon John]

I want to share my recent experience of breaking down at a charging station and the solution. This was only my 2nd attempt at charging away from home.

I arrived early at South Mimms Services on the M25, read the instructions on the charger, paid and then plugged in. Nothing was happening so I started ‘messing around’ with it, literally. Taking the charger out, putting it back in, paying again with my card etc., then HV battery light went red, low voltage battery went red, Power system severe fault light was showing. I contacted MG assist, I had the number saved in my phone, and recovery came out within about 30mins, (thank goodness as I was on my way to Heathrow to pick up my wife & daughter).

He told me he had an MG5, same colour with the same fault last week and on that one he just disconnected the 12v battery. I had read that disconnecting the battery may reset the car, but I had no 10mm spanner with me SO PLEASE PUT ONE IN YOUR CAR IMMEDIATELY ?. He tried this 3 times, but it never reset, He then disconnected the battery again and connected the On Board Diagnostics (OBD) connector and cleared the error codes, IF YOU HAVE ONE PLEASE PUT THIS INTO YOUR CAR, I HAVE ?. This time it worked, and I plugged into a different charging station (see photo) and hey presto it worked.

I thought it worth sharing as most of us can figure out when an engine goes wrong but not an EV, anyway I do love my car and hopefully learnt some valuable lessons.

 

[MickeySw]

While using a spanner should be straight forward, clearing DTCs isn’t, so just having a dongle in the car isn’t enough; you need to practice beforehand (connect dongle to car, pair via Bluetooth, download and setup app, read and clear DTCs)

Preparation paid off for me; was back on the road in less than 5min after a CCS charging session gone wrong turned off the HV battery last month.

 

[boomish]

Great tips, knew about them but didn’t think to actually put the tools in the car doh..

 

[admiralross2400]

I know there's been a few chats about it elsewhere, but is there a definitive answer to which OBD to use (and what app)?

 

[dragon2611]

I think carscanner can do it, but I wasn't patient enough to let it finish scanning the various ECU's last time i played with it and went for the 12v battery trick on my prefacelift

 

[MickeySw]

I know there's been a few chats about it elsewhere, but is there a definitive answer to which OBD to use (and what app)?

Car Scanner App on Android using OBD Link LX (Bluetooth) worked for me..

 

[shpub]

If you reset the 12v supply, disconnect the black wire that sits on the rectangular sensor only. There is no need to undo the battery terminal itself. Make sure that everything is off to prevent/reduce any sparks. After the reset, don't be surprised if a lot of error messages saying the front collision, auto hold etc etc are displayed. This will go after you have driven a little distance like 2-300 yards or so and the car will be back to normal. Worth checking the car settings as well in case any of those have been reset.

As for OBD-II, Car scanner worked fine for me - I selected the MG5 facelift car model and that worked OK. DTC clearing worked OK. AS for adapter the OBDlinkLX is great but a chinese copy ELM bluetooth reader I had lying around also worked at the first attempt. Both scanned and read the messages very quickly.

 

[shpub]

If you reset the 12v supply, disconnect the black wire that sits on the rectangular sensor only. There is no need to undo the battery terminal itself. If you do, then the world will end.... Actually it upsets the current sensor so until it has sorted itself out, you can't trust any associated readings.

I modded mine so I did not need to use a 10mm spanner.

Quick disconnect for MG5 battery

Just replaced the m6 nut on the battery terminal with a M6 thredded knob that can be undone by hand without a spanner should the need arise. I then cable tied the original nut around the terminal so i didn't loose it. Means I can disconnect and reset the car without the need of a 10mm spanner...

www.mgevs.com

 

[jasonh]

If you reset the 12v supply, disconnect the black wire that sits on the rectangular sensor only. There is no need to undo the battery terminal itself. Make sure that everything is off to prevent/reduce any sparks. After the reset, don't be surprised if a lot of error messages saying the front collision, auto hold etc etc are displayed. This will go after you have driven a little distance like 2-300 yards or so and the car will be back to normal. Worth checking the car settings as well in case any of those have been reset.

As for OBD-II, Car scanner worked fine for me - I selected the MG5 facelift car model and that worked OK. DTC clearing worked OK. AS for adapter the OBDlinkLX is great but a chinese copy ELM bluetooth reader I had lying around also worked at the first attempt. Both scanned and read the messages very quickly.

Have you any pictures of this black wire please for reference, as its a great tip.

 

[shpub]

I put the link in the next post #8