Smart Key Not Detected Car Not Starting

ajitsingh334 · Sep 3, 2022

Help Please!!

My MG ZS EV 2021 Exclusive - is in a Bodyshop for some minor repairs. It was driving and starting all ok.

However, after the front driver door loom was unplugged. The car wouldn’t start. There are 2 messages on the dash ‘Smart Key Not Detected’ & ‘Put Key In Backup Position’.

I have put the key in the front cup holders as per manual instructions. Still same error.

All The doors lock and unlock after the door loom has been plugged back in. Still no luck.

I only have 1 key for the car.

Any advice/help to get the car back on would be much appreciated. The car has the handbrake on and not in neutral so a pain for the garage as it cannot be moved.

Thanks in advance
Ajit

Jomarkh · Sep 3, 2022

I have got to ask why did you only get one key?
Try disconnecting the 12v battery for 30 minutes.

Kithmo · Sep 3, 2022

Does the key lock and unlock the doors ok ?

ajitsingh334 · Sep 3, 2022

Jomarkh said:
I have got to ask why did you only get one key?
Try disconnecting the 12v battery for 30 minutes.

Bought the car second hand and only got one key. I will try disconnecting the battery thanks.

ajitsingh334 · Sep 3, 2022

Kithmo said:
Does the key lock and unlock the doors ok ?

Yes

Kithmo · Sep 3, 2022

ajitsingh334 said:
Yes

That rules out a low fob battery.

MichaelJHunt · Sep 3, 2022

The car is still under warranty. Can you get it to a dealer?

Coulomb · Sep 4, 2022

Is the car currently near a mobile tower? I find that my Mk1 ZS EV is affected by strong mobile tower signals. I have to be careful where I park in a shopping centre that has two mobile towers. Sometimes it can just barely lock the car, then when I return, I sometimes have trouble unlocking. I find that positioning the fob just right (near the gear selector) can avoid key not detected errors. Once ~30 metres away from the towers, I have no problems with the fob.

AgnesFaafiti · Mar 23, 2023

Did you end up getting this fixed? I in the same boat at the moment & have tried everything you have??‍

JeffE · Jun 2, 2023

AgnesFaafiti said:
Did you end up getting this fixed? I in the same boat at the moment & have tried everything you have??‍

I am having the same issue as well. Did anyone manage to find a fix for this?

Gregson 8096 · Dec 3, 2023

Same problem has someone found a solution yet ?
Thanks in advance

Coulomb · Dec 3, 2023

I have found no definitive solution to the mobile tower problem. However, I'm basically only affected in one location, and I've gotten used to always parking in an area of that carpark where I know it's far enough away from the mobile phone towers that I have no problem. I don't even think about it any more, it's just habit. Fortunately that safe parking area nearly always has a spare space, and it's convenient to the shops I use.

It's possible that metalwork supporting shade cloth that was installed a year or two ago has helped shield that area and most car parking spots.

When I can't park in the known safe area, shifting my leg so that the fob in my pocket is closer to the door handle always seems to work. Again, it's an automatic habit now, so I barely think about that either.

Edit: Are drivers having the key not detected problem or the mobile tower too close problem? Is it possible that they are the same problem? My apologies for ranting if the main problem is unrelated to mobile towers.

Bassiavet · Mar 29, 2025

Hello! The same problem here, but with an MG4 EV, the car isn't recognising the smart key, it can open and close with a fob, but the car is bricked and won't start, even though the key fob is in the back up position as per manual. I tried both fobs without success, didn't try to remove the 12V battery yet, the car is showing the following messages:
Any known solution found?

Coulomb · Mar 29, 2025

Bassiavet said:
didn't try to remove the 12V battery yet,

I would try that first.

Are you sure that you have the key in the correct manual-start position? That should be independent of fob battery level, mobile tower interference, and so on, I would think.

Bassiavet · Mar 29, 2025

Coulomb said:
I would try that first.

Are you sure that you have the key in the correct manual-start position? That should be independent of fob battery level, mobile tower interference, and so on, I would think.

Yes I checked the manual! I have managed a work around method to make the vehicle turn on and drive by the following:
-Unlock the car as usual by using the fob.
- Sit in the driver seat ( a warning will show and the vehicle wont start, so I would lift my weight from the seat, use the fob to unlock the car again, put my weight back and the car would start.
-If I press the brake I would get the warning again and the shifter would be stuck at neutral mode;
- So then I have to use the fob again to unlock the car in order to get it ready.
-After I drive the warning will keep beeping for a whole 5 mins.
I took it to the dealership, they kept it and gave me a zs ev until they fix hopefully the problem. I Will keep you posted if they fix it!

Chris Law · Mar 29, 2025

Don't know if this applies to your vehicle and not a permanent solution, but just in case. The iSmart app for my 2023/4 ZS EV Lux/LR offers a digital key. It needs setting up before first use but it does work.

Bassiavet · Mar 29, 2025

Unfortunately the application doesn't work in my country, the dealership said they cannot upgrade my factory 2023 infotainment system, they said they will update the hardware stuff hopefully it will help fixing my problem.

Chris Law said:
Don't know if this applies to your vehicle and not a permanent solution, but just in case. The iSmart app for my 2023/4 ZS EV Lux/LR offers a digital key. It needs setting up before first use but it does

Jto · Apr 5, 2025

ajitsingh334 said:
Help Please!!

My MG ZS EV 2021 Exclusive - is in a Bodyshop for some minor repairs. It was driving and starting all ok.

However, after the front driver door loom was unplugged. The car wouldn’t start. There are 2 messages on the dash ‘Smart Key Not Detected’ & ‘Put Key In Backup Position’.

I have put the key in the front cup holders as per manual instructions. Still same error.

All The doors lock and unlock after the door loom has been plugged back in. Still no luck.

I only have 1 key for the car.

Any advice/help to get the car back on would be much appreciated. The car has the handbrake on and not in neutral so a pain for the garage as it cannot be moved.

Thanks in advance
Ajit

Buy a 2nd and have both reprogrammed to the car.

Bassiavet · Apr 5, 2025

They took my car for few days and gave me a new zs ev as a replacement, and they upgraded some software, not the infotainment, it still the factory software.
They called me after few days and said that the Body control module (BCM) needs to be replaced, they ordered it, I took my car back today and I will bring it back to install it once it arrives. I will update here if it works.

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