Mercedes-Benz

Mercedes-Benz Key Fob Programming San Jose — EZS/EIS, Chrome Key & Infrared Remote

Mercedes-Benz 📅 April 2026 ⏲ 7 min read ✎ Cabrera's Key Fob Team

Mercedes-Benz has used two distinct remote channel technologies across its key generations — infrared on older models, RF/UHF on current ones — plus an ignition-mounted security module (the EIS/EZS) that every key must be individually programmed into. The result is a key system that's technically impressive and notoriously expensive at the dealer. We program Mercedes keys on-site across all generations, at significantly less than dealer pricing — same-day, wherever your vehicle is parked.

Mercedes-Benz key fob programming San Jose EZS EIS Chrome Key specialist

Mercedes Key Technology: EZS/EIS and the Two Remote Channels

Mercedes-Benz key systems have two layers worth understanding:

Layer 1 — The Immobilizer (EZS/EIS):
The EZS (Electronic Ignition Switch) on W203/W209/W211 models and the updated EIS on W204/W205 and later is a module physically mounted in the ignition barrel. When a key is inserted (or detected via Keyless-Go proximity), the EIS reads the key's transponder chip (typically a NEC or Motorola chip). If the chip ID is in the EIS memory, engine start is authorized. If not — even if the mechanical blade fits — the car won't start.

Layer 2 — The Remote Channel:

Infrared remote (IR) — 1996–2009 era: The W203 C-Class, W211 E-Class, W220/W221 S-Class, and SLK/CLK models use an infrared emitter in the key fob to lock/unlock. The IR signal must be aimed at the IR receiver in the door jamb. Very different from standard RF fobs — cannot be programmed with generic remote programmers.
UHF RF remote — 2009–present: Current C-Class (W204/W205/W206), E-Class (W212/W213), GLE (W166/W167), GLS (X166/X167), and G-Class use standard 433MHz/315MHz RF signals for lock/unlock, with KEYLESS-GO proximity detection built into the current Chrome Key platform.

Our equipment handles both IR and RF Mercedes keys, plus the EIS transponder programming for all models.

Mercedes-Benz Models We Service Most in San Jose

C-Class (W203/W204/W205/W206): The volume leader. Chrome Key on W205/W206. Infrared on W203. Programming from $295.
E-Class (W211/W212/W213/W214): Executive sedan. W211 uses infrared; W212 onward uses RF. Programming from $295.
S-Class (W220/W221/W222/W223): Flagship. Chrome Key with KEYLESS-GO. W220/W221 use infrared. Programming from $325.
GLE (W166/W167): Popular luxury SUV in Almaden, Los Gatos, Saratoga. Programming from $295.
GLS (X166/X167): Full-size luxury SUV. Programming from $325.
G-Class / G-Wagon (W463/W464): Iconic off-roader. Very common in South Bay luxury market. Programming from $325.
AMG GT / C63 / E63 / GLE 63: Performance variants use the same EIS/Chrome Key platform as standard models. Programming pricing same as base model by generation.
GLA / GLB / CLA: Entry-level Mercedes SUVs. Chrome Key with RF. Programming from $275.

The Mercedes Chrome Key — What It Is and Why It Matters

Since roughly 2014 on the W205 C-Class and 2016 on the W213 E-Class, Mercedes shifted to the Chrome Key (also called the Comfort Key or Keyless-Go Smart Key). This is the silver metal-bodied fob with a built-in mechanical blade (fold-out or removable). The Chrome Key handles:

UHF lock/unlock remote signal
Passive proximity detection for Keyless-Go (if equipped)
Transponder chip communication with the EIS

The Chrome Key contains a CR2025 or CR2032 battery and a NEC/Motorola transponder chip. If the battery dies completely, the Chrome Key can still start the car by placing it in the wireless charging tray or specific dashboard location — but remote entry and KEYLESS-GO will be inactive until the battery is replaced. Our battery replacement guide has the specific steps for Chrome Keys.

Mercedes Dealer vs. Mobile Locksmith

Model	MB of Stevens Creek (Est.)	Cabrera's Key Fob
C-Class / GLE Chrome Key	$450–$600+	Starting from $295
E-Class / S-Class Chrome Key	$500–$700+	Starting from $325
G-Class / GLS	$550–$750+	Starting from $325
Tow to dealer (if no spare)	$75–$150 additional	Not needed — we come to you

What to Have Ready

Vehicle registration in your name
Government-issued ID matching registration
VIN (windshield or door jamb)
Model, year, and class (e.g., "2021 W206 C300")
Whether your vehicle has KEYLESS-GO (check if you have door handles with sensors)
Any existing working keys

Mercedes key failed in San Jose, Sunnyvale, or Los Gatos? EIS/Chrome Key specialists — same-day mobile service, no dealer required.

📞 Call (408) 794-8016

Frequently Asked Questions

Yes. We program Mercedes-Benz key fobs and smart keys on-site using MB-compatible diagnostic equipment covering the EZS/EIS immobilizer system. This includes infrared remote keys (pre-2010) and current Chrome Key/proximity smart keys. Most C-Class, E-Class, S-Class, GLE, and GLS models from 2003–2024 are covered.

The EZS (Electronic Ignition Switch) on older models and EIS (updated version) on newer ones is the ignition-mounted module that authenticates the key. The key must be programmed into the EIS/EZS memory to authorize engine start. A key not in the module's memory will turn the ignition without starting the engine.

Mercedes-Benz key fob programming through Cabrera's Key Fob starts from $295 for C-Class and GLE models (versus $500+ at Mercedes-Benz of Stevens Creek). E-Class, S-Class, GLS, and G-Class start from $325. Call (408) 794-8016 for a vehicle-specific quote.

The Mercedes Chrome Key (also called the Comfort Key or Keyless-Go key) is the silver metal-bodied fob used on current C-Class, E-Class, S-Class, and GLE/GLS models. It handles both the UHF lock/unlock channel and the proximity detection. We program Chrome Keys on-site using Mercedes XENTRY-compatible diagnostic equipment.

If the key turns in the ignition but the engine won't start, the most common causes are: (1) the EIS/EZS module doesn't recognize the key's transponder chip, (2) the key's transponder chip is damaged, or (3) there's an EIS/EZS module fault. We diagnose these on-site using Mercedes diagnostic equipment. Call (408) 794-8016.

🔑

Cabrera's Key Fob Auto Locksmith

San Jose's trusted 24/7 mobile auto locksmith team. Licensed, insured, and bilingual — key fob programming, lockout service, transponder keys, and ignition repair across the South Bay. Hablamos Español. Call (408) 794-8016 anytime.