Immobilizer Service & IMMO Reset San Antonio

S.A. Locksmith & Security provides expert immobilizer service, IMMO reset, and security module programming for all vehicle makes and models in San Antonio, Texas. The immobilizer is your vehicle’s anti-theft system that communicates between the key/fob and the ECU. When this system malfunctions — the car won’t start, the security light flashes, or a new ECU needs to be matched — we diagnose and resolve the issue using manufacturer-level tools.

What Is an Immobilizer & How Does IMMO Reset Work?

Your vehicle’s immobilizer system verifies that the correct key or smart fob is present before allowing the engine to start. It uses encrypted communication between a transponder chip in the key and the immobilizer module (integrated into the ECU, BCM, or a standalone unit). IMMO reset clears the security codes and allows new keys to be registered to the vehicle.

When you need immobilizer service:

Car won’t start — security/immobilizer light flashing
All keys lost — need to program new keys from scratch
After ECU replacement — immobilizer needs to be synchronized
Key not recognized after battery replacement
Immobilizer module failure or water damage
Used vehicle with missing key history

ECU Brands & Systems Covered

BMW EWS2, EWS3, EWS4, CAS1-CAS4, FEM, BDC — all BMW models 1995+
Mercedes-Benz EIS/EZS, ESL, DAS/FBS4 — all Mercedes models 1999+
Ford PATS (Passive Anti-Theft System) — all Ford, Lincoln, Mercury, Mazda Tribute/B-Series
GM Passlock, Passkey III+, VATS — all Chevrolet, GMC, Cadillac, Buick, Pontiac, Saturn, Oldsmobile, Hummer
Toyota / Lexus Smart Key System, G-Chip, H-Chip — all Toyota/Lexus models
Honda HISS (Honda Ignition Security System) — all Honda, Acura models
Nissan NATS (Nissan Anti-Theft System) — all Nissan, Infiniti models
Hyundai / Kia Immobilizer, Smart Key — all Hyundai, Kia, Genesis models
Mazda Immobilizer (TI 4D-60/4D-63), Advanced Keyless (Hitag Pro)
VW/Audi Immobilizer III, IV, V (IMMO3-5) — all VAG platform vehicles
FCA/Stellantis SKIM, SKREEM, WIN — Jeep, Dodge, Chrysler, RAM

Vehicle Brands We Service

Domestic: Ford, Lincoln, Mercury, Chevrolet, GMC, Cadillac, Buick, Pontiac, Saturn, Oldsmobile, Hummer, Chrysler, Dodge, Jeep, RAM

Japanese: Toyota, Lexus, Honda, Acura, Nissan, Infiniti, Mazda, Subaru, Mitsubishi

European: BMW, Mercedes-Benz, Audi, Volkswagen, Porsche, Volvo, Land Rover, Jaguar, MINI, Fiat, Alfa Romeo

Korean: Hyundai, Kia, Genesis

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Immobilizer Service & IMMO Reset FAQ

How much does immobilizer reset cost?

IMMO reset/service ranges from $150-$500 depending on the vehicle and system complexity. BMW CAS/FEM, Mercedes EIS, and all-keys-lost situations are at the higher end. Call (210) 348-3677 for pricing.

Can you reset the immobilizer if all keys are lost?

Yes. We handle all-keys-lost situations for virtually every make and model using professional tools (AVDI, AutoHex, Xhorse VVDI, Autel IM608). We reset the immobilizer and program new keys on-site.

Why won't my car start after ECU replacement?

The replacement ECU’s immobilizer data doesn’t match your keys. We synchronize the new ECU with your existing keys or program new keys to match — no dealer needed.

Is immobilizer bypass legal?

We perform immobilizer reset and key programming — not bypass. This is the same legitimate process dealers use. We require proof of vehicle ownership before any immobilizer work.

How long does immobilizer service take?

Most immobilizer resets and key programming are completed in 30-90 minutes on-site. Complex systems (BMW FEM/BDC, Mercedes EIS) may take 1-2 hours.

Request a Locksmith

S.A. Locksmith & Security is a full-service, 24/7 locksmith located in San Antonio serving the greater SA area. No project is too big or too small.

📞 (210) 348-3677

We Accept All Major Credit Cards

Note: Pricing and availability may vary. Smart key programming requires professional equipment. Some services may require vehicle VIN verification. All work is backed by our 90-day warranty on parts and labor and manufacturer warranty on hardware. S.A. Locksmith & Security — Licensed (LIC# B18010), Insured, BBB Accredited (A+ Rating). 11401 West Ave, San Antonio, TX 78213. All brand names, logos, and trademarks are the property of their respective owners. S.A. Locksmith & Security is an independent locksmith service provider and is not affiliated with any automobile manufacturer or dealership. 10% Military & Veteran Discount — show valid military ID at time of service.

Need Immobilizer Service & IMMO Reset in San Antonio?

Contact S.A. Locksmith & Security for professional immobilizer service & immo reset. All vehicle brands supported. 24/7 emergency service available.