These instructions apply to the MG HS Mk2 2024-present.
For other models, please choose your vehicle here.
If the smart key on your MG HS Mk2 (2024–present) has a flat battery — or the cluster shows “Smart Key Not Found” or “Please Put the Key in Standby Starting Position” — you can still start the car. The HS has a standby (backup) starting position that reads the key directly, so a dead fob battery won’t strand you. Here is how.
Why a Dead Fob Still Starts the Car
Your HS normally detects the smart key by radio. When the fob battery is too weak to transmit — or something nearby is jamming the signal — the car can instead read the key at close range through a backup antenna at the standby starting position. The passive chip in the key needs no battery for this, so the car starts even with a completely dead cell.
How to Start the MG HS With a Dead Key Fob
- Get in using the mechanical blade. Slide the emergency key out of the fob and unlock the driver’s door with it.
- Hold the smart key to the standby position — place it against the START/STOP switch at the position and angle shown in your handbook, so the car can read it up close.
- Put the gear selector in P (or neutral) and press the brake pedal.
- Press the START/STOP switch to start the car.
- Once running, fit a fresh CR2032 cell soon — see our MG HS key fob battery guide.
⚠️ Don’t keep cranking. If the car will not start after a few attempts even with the key in the standby position, stop and seek help — a privately-cut key that has not been programmed to the car cannot start it, as the immobiliser will not recognise it.
If It Still Won’t Start
- Try again with the key held flat against the switch — the standby antenna only works at very close range.
- Fit a new fob battery and retry; a fresh CR2032 often restores normal keyless detection.
- Rule out a flat 12 V battery. If the whole car is dead (no lights or dash), the vehicle’s own 12 V battery may be flat rather than the key — that needs a jump-start, not a key fix.
- If the immobiliser light stays on with a genuine, in-range key, the key may not be recognised — that is a dealer matter.
Frequently Asked Questions
How do I start my MG HS if the key fob battery is dead?
Unlock with the mechanical blade, hold the smart key against the START/STOP switch in the standby starting position, press the brake with the car in P, then press START.
Where is the standby starting position on the MG HS?
At the START/STOP switch — you hold the key against it at the position and angle shown in the handbook so the backup antenna can read the key at close range.
Will a flat fob battery leave me stranded?
No. The passive chip in the key works without a battery, so the standby position starts the car. You only lose the remote lock/unlock buttons until you fit a fresh cell.
My HS still won’t start with the key in the standby position.
Check the 12 V battery isn’t flat (whole-car dead vs just the key), and that the key is a genuine programmed one. After a few failed attempts, seek help rather than keep trying.
What battery does the fob take?
A CR2032 3 V coin cell — see our key fob battery replacement guide.
Independent guide — not affiliated with MG. Always follow your official service manual and safety precautions. Read our full disclaimer.