MG5 Stop Start stuck in Standby Mode.

[Colinw]

Recently Stranded MG Ev5 , during charge at Podpoint, experienced a short period of Stop Start button clicking during the charge, with Amber and green lights flickering. Then the click noise stopped, Charged to approx 90% Drove away OK after charge period, and travelled for 1hr.
Then parked up and Stop Start button would not switch off- Ev stopped but car was stuck in Standby Mode with lights Radio all on. Was unable to restart Ev mode. Stranded for 10 hours and obviously 12v battery drained. When finally recovered a new battery was fitted and Startstop button was still stuck on and unable to switch to EV Ready mode. Seems like the Stop Start button has to go off to reboot the EV.
But no matter what we did this stuck on Standby Mode. Any Ideas.

 

[Jomarkh]

Not heard of that before.
Who replaced the 12v battery did they do a diagnostic check?

 

[Colinw]

It had just been in for its first service 1 day before breakdown. RAC tried a new battery but no Joy. They tested the original and said a cell had failed. Well it was certainly flat because it was running 12 volt system for approx 8 hrs then died because we could not switch off the electronics.
We had to be rescued home on a flat bed.
I'd now dropped car off @ MG to look at.

RAC plugged in computer but had no access, the electronics were blocked from them looking at diagnostics. Not a good experience.

 

[BugEyed]

Not a pleasant experience for sure. Another example of the need to carry a 10mm spanner.

I wonder whether you had updated software at the service?

 

[Gomev]

RAC plugged in computer but had no access, the electronics were blocked from them looking at diagnostics. Not a good experience.

I take it you didn't use the MG Assistance from the AA that comes with the car. I believe they can access the diagnostics.

 

[Colinw]

Lesson learned, I only found out about MG assist when it was too late. My Fleet/lease company told me nothing about MG Assist. They have now recovered it to garage, but stop start button is still clicking. It sounds like a relay is constantly on/off. I will infuture make sure 10mm spanner is ready.

 

[vanillapod]

Lesson learned, I only found out about MG assist when it was too late. My Fleet/lease company told me nothing about MG Assist. They have now recovered it to garage, but stop start button is still clicking. It sounds like a relay is constantly on/off. I will infuture make sure 10mm spanner is ready.

Just reading this thread as we have encountered exactly this problem in our MG5 (2021 SW).

Yesterday stop start button would only turn off to amber, meaning the car could not be locked. Strangely an hour later it locked fine. This morning the same thing happened, but when I long-pressed the stop start button there was a clicking noise from behind the button (to the right of the dashboard), and eventually it powered off.

Colinw, what was the eventual solution for you? Fortunately we can still drive and the 12V is ok, but keen to get to the bottom of this.

Thanks

 

[Gomev]

Silly question I know but just for elimination purposes....when you go to turn off you don't have your foot on the brake do you ?

 

[Deleted member 13103]

Silly question I know but just for elimination purposes....when you go to turn off you don't have your foot on the brake do you ?

Another silly question, but what difference does it make to keep one's foot on brake when switching off, I often get 'HV Battery shutdown' in amber, I then switch off but usually I think my foot's still on the brake, but it always goes to 'Ready' in green...

 

[Gomev]

Another silly question, but what difference does it make to keep one's foot on brake when switching off, I often get 'HV Battery shutdown' in amber, I then switch off but usually I think my foot's still on the brake, but it always goes to 'Ready' in green...

I don't know and can't check as I no longer have the vehicle, but sillyly, I thought it might be useful for you to find out for elimination purposes, a good technique for diagnostic purposes.
Once in Park I always just pressed the Stop/Start, foot off brake. In my case it never went green/orange, showed any HV battery messages or anything else, it just switched off.

 

[Deleted member 13103]

I don't know and can't check as I no longer have the vehicle, but sillyly, I thought it might be useful for you to find out for elimination purposes, a good technique for diagnostic purposes.
Once in Park I always just pressed the Stop/Start, foot off brake. In my case it never went green/orange, showed any HV battery messages or anything else, it just switched off.

Just to clarify, the car regularly does the HV Battery thingy upon initial startup, having pressed the stop/start button with foot on brake, I just keep my foot on the brake and re-press the stop/start button for it to startup 'ready', funnily enough it did it this morning, but no big issue really.

 

[vanillapod]

Silly question I know but just for elimination purposes....when you go to turn off you don't have your foot on the brake do you ?

No, only when starting.

We've had this issue of the car not turning off beyond amber a few times over the last few days. Each time it does turn off on its own after about an hour, and once it did when I long-pressed the on/off button, which is when the clicking noise occurred. Twice, we got the HE battery shut off message, and then we couldn't actually drive the car. I resolved that one by disconnecting the 12v battery, but the next time we tried to turn the car off it still only went to amber.

This all happened on Tuesday, and again today (Friday). The only thing I can think of is that each time it's done this has been after a period of heavy rain. When it's been dry it's been fine. We have our car parked outside on our drive and I'm wondering if there is any water or damp ingress around of near some of electrics related to the start/stop button. Does anyone have any ideas about this or experience of this?

 

[RichP]

I’ve had this when the pipe connector for the rear wash wipe detached which sprayed washer fluid behind the dash, yes really. It’s an appalling design. The fluid caused the start stop switch to go crazy.

 

[vanillapod]

Thanks RIchP, this is almost certainly it... Coincidentally, there's been no washing fluid coming out the front wiper nozzles this week, and I was going to fill it up today. But, having had a look, there's still some washing fluid in the reservoir. So, somewhere the pipe has become disconnected and the leak is probably responsible for the start stop switch issues. A Quick Look at other threads on this forum, and I can see this that weak washing fluid pipe connections is a but of an issue with MG5s...

I've had a look under the bonnet and taken off as much as I can, but can't get the grill off in the photo here (which is drive side behind dashboard).

RichP, did you repair yourself, or take it to the garage/dealer?

 

[ALANB]

Should be fixed under warranty, but it usually happens in the bit next to the windscreen.
The white cable tie is the pipe that needed that to stop the issue. This from a Facebook post for someone else. It's where the pipe freezes and the pump forces the connectors off.....can also happen in the boot door. Solution.....use concentrated mix of screen wash to stop freezing (to be fair this has happened in a number of cars I have owned over the years not just MG's. )

 

[RichP]

Thanks RIchP, this is almost certainly it... Coincidentally, there's been no washing fluid coming out the front wiper nozzles this week, and I was going to fill it up today. But, having had a look, there's still some washing fluid in the reservoir. So, somewhere the pipe has become disconnected and the leak is probably responsible for the start stop switch issues. A Quick Look at other threads on this forum, and I can see this that weak washing fluid pipe connections is a but of an issue with MG5s...

I've had a look under the bonnet and taken off as much as I can, but can't get the grill off in the photo here (which is drive side behind dashboard).

RichP, did you repair yourself, or take it to the garage/dealer?

The dealer did it. When I took it in they said “oh not another one” telling me it’s a dash out job to fix it!