2021 Mercedes-Benz GLA Key Replacement in Los Angeles

The 2021–2026 GLA uses the same key setup, so everything on this page applies to those years too. The full picture is on the Mercedes-Benz GLA key guide.

2021 Mercedes-Benz GLA: key facts

Key type: Smart / proximity key
Push-to-start: Yes
Transponder chip: Varies by trim — we confirm by VIN
Programming: Dealer-only (we'll tell you before you spend anything)
All keys lost: We can originate new keys on site

H247 GLA on the MFA2 platform — its W177 A-Class sibling's EZS is documented as FBS4 by Abrites, but we did not verify H247-specific key documentation this session. Added/replacement keys are assumed dealer-only; we confirm the current procedure per job.

What kind of key does a 2021 GLA use?

The 2021 GLA (the H247 generation, built on Mercedes' MFA2 platform) uses a smart proximity key. You carry the fob, the car senses it, and you start the engine with the push button instead of turning a key. Tucked inside the fob is a mechanical backup key for the door lock, for the day the battery dies or the car can't read the fob.

For an owner, the practical meaning is that a replacement is not a hardware-store copy. The fob has to be coded to your specific car, and for this model we treat that as dealer-only work, ordered against your VIN. That is why a lost or damaged fob usually means a multi-day wait rather than a same-afternoon fix.

The immobilizer family listed for this setup is FBS4 (DAS4). Please read the note near the end of this page about what we have and have not confirmed for this exact year.

Duplicate key or all keys lost: what changes on this car?

If you still have a working fob, the data for this year says the original key is not required to make a duplicate. Even so, having one good fob in hand makes everything calmer. If you are down to a single fob, getting a spare before something goes wrong is the sensible move.

All keys lost is also possible on this setup. It simply takes more steps, because there is no fob to use as a reference. The car is identified by its VIN, ownership is verified, and the new fob is ordered and coded against that information.

Have these ready when you call:

Your VIN (usually visible at the base of the windshield, and printed on your registration)
Proof the car is yours, plus a photo ID
How many fobs you still have, even if one is damaged or water-soaked
Where the car is parked right now

Call us and tell us the year, model, and how many working fobs you have left.
We ask for the VIN and ownership details.
We confirm the current procedure for your GLA by VIN and tell you plainly whether it goes through the dealer and what the wait looks like.
If the car is stuck somewhere, we talk through the situation with you and can come out in a mobile van to assess it.
When the new fob is in hand, every fob gets checked: doors, push-button start, and the mechanical backup key.

Is it really the key? Common GLA problems

Not every 'my key stopped working' call needs a new fob. On this car the usual culprits are listed below, and the first and last are often cheaper to fix than a replacement.

A dead fob battery, where the car reports 'key not detected'
A lost or damaged fob, which needs a VIN-coded dealer order and a multi-day wait
A water-damaged fob
Keyless antenna or start-button faults that mimic a bad key

Locked out or need a locksmith now?

We answer around the clock, every day of the year.

Call (213) 577-1366

What affects the price of a GLA key replacement?

We won't quote a number without knowing your situation, and you shouldn't trust anyone who does on a smart key without a VIN. These are the things that move the cost:

Whether you have a working fob (a spare) or every key is gone
How many fobs you need coded to the car
The dealer order for a VIN-coded fob, since this model is treated as dealer-only
Whether the fob is merely out of battery, water-damaged, or truly dead
Diagnosis time if the keyless antenna or start button turns out to be the real fault
Where the car is and what hour you need help

What we have not verified, and who you'd be calling

Here is the honest part. The GLA's A-Class sibling (the W177) is documented as using FBS4 in its ignition system. We did not verify key documentation specific to the H247 GLA, so we treat the chip family as unconfirmed. Added and replacement keys are assumed to be dealer-only, and we confirm the current procedure for your car by VIN on every job rather than guessing.

Wilshire Lock & Key has been in business since 1987. We run a storefront at 10740 Wilshire Blvd in Westwood plus mobile service vans, and we serve 140 cities across Los Angeles and Ventura counties. It is one company, with no dispatch middlemen, and David, the owner and lead technician, oversees the work. California requires locksmith companies to hold a BSIS LCO license, and you should ask any locksmith, us included, for it before work begins.

For wider background, see our pages on Mercedes-Benz keys, GLA keys across model years, and car keys in general. If you'd rather write than call, use our contact page.

Frequently asked questions

Can I get a replacement 2021 GLA key without the original?

Yes. The data for this year says an original key is not required, and all keys lost is possible. It involves VIN and ownership verification, and a fob ordered and coded to your car.

Is a 2021 GLA key dealer-only?

We treat added and replacement keys for this car as dealer-only. Because we haven't verified H247-specific documentation, we confirm the current procedure by VIN on each job and tell you honestly what applies.

My GLA says 'key not detected'. Do I need a new key?

Not necessarily. A dead fob battery is a common cause. The mechanical backup key inside the fob can open the door. Antenna or start-button faults can mimic a bad key, so it is worth diagnosing before ordering a fob.

How long does a lost GLA key take to replace?

Plan on a multi-day wait, because the fob is a VIN-coded dealer order. We won't give you a made-up timeframe. We'll tell you what the process looks like once we have your VIN.

Does the 2021 GLA have a backup key if the fob dies?

Yes. The smart fob includes a mechanical backup key, which works the door lock when the battery is dead or the car can't read the fob.

Will water damage kill my GLA fob?

It can. Water-damaged fobs are a known problem on this setup. If yours got wet, stop pressing buttons and call us so we can tell you whether it is worth saving or time to order a replacement.

Do you come to me, or do I have to bring the car in?

Both work. We have a storefront at 10740 Wilshire Blvd in Westwood and mobile vans. Call (213) 577-1366 any hour, and we'll sort out the best approach for where the car is.

We cover all these cities

Reviewed by David, Owner & Lead Technician, Wilshire Lock & Key — in the locksmith trade since 1987.

Last updated 2026-10-11.