"No Key Detected" — Immobilizer Repair in Dallas–Fort Worth
Mobile Service Across Dallas–Fort Worth
Key not detected. Security light flashing. Cranks then dies. The immobilizer is doing its job badly — refusing a legitimate key — and the fix runs from a $10 coin cell to a module repair. We diagnose and repair immobilizer faults for every major make at your location across DFW, and we start with the cheap causes first.
Quick Answer
As of July 2026, immobilizer repair in Dallas–Fort Worth runs $150–$350 for credential and re-registration work and $250–$700 when antenna hardware or the module itself needs replacement, through our mobile service — with the free phone triage often solving the cheap causes before any visit. Call (817) 813-8746 with your VIN for a firm all-in quote.
Typical DFW Pricing
| Service | Typical range | Notes |
|---|---|---|
| Immobilizer / key credential reprogramming | $150–$350 | Most common resolution |
| Module-side repair | $250–$700 | When the antenna ring, receiver or module is at fault |
| Diagnostic visit | $95–$185 | Often credited toward the repair |
Key Side or Car Side?
A second working key answers it instantly: if the spare starts the car, the problem is the key; if neither works, it is the vehicle. No spare? The diagnostic visit reads what the immobilizer actually sees — Honda’s flashing green key, Ford’s PATS light, Toyota’s security lamp and the European variants each tell a specific story.
How It Works
Call With Your VIN
Every module and security job is VIN-specific. Tell us the year, model and symptoms, and we confirm coverage and quote before anyone is dispatched.
Diagnose First, Then Fix
We confirm which module or system is actually at fault before selling you a repair — a large share of “failed module” calls turn out to be a credential, connector or configuration problem that costs far less.
Programmed, Tested, Done On Site
Programming happens at the vehicle with manufacturer-level software and stable voltage, followed by a full function test before we leave.
Platforms We See Most
- Honda / Acura — Green-key-light rejections, antenna ring failures
- Ford PATS — Rapid-flash theft light no-starts
- GM PassLock / Passkey — Crank-stall-wait patterns
- Toyota / Lexus — Security lamp faults on G/H-chip and smart-key cars
- VW / Audi — Immo generations 1–5, cluster-linked
- Nissan / Infiniti — NATS faults entwined with the BCM
The Honest Boundary
Truth in diagnosis: an immobilizer that rejects keys is guilty until proven innocent, but the guilty party is often a five-dollar coin cell, a chafed antenna wire or a low 12-volt battery. We work the suspect list from cheapest to priciest and charge for the fault we actually find — not the scariest one on the list.
Frequently Asked Questions
The fob is right here in my hand, yet the dash claims there is no key — why?
Dead fob cell, a fob that lost registration, a failed antenna ring, or interference. Try the manufacturer’s backup start position first (fob against the button or in the pocket slot), then call — we diagnose which link failed.
The car cranks and dies immediately — engine or immobilizer?
Almost always immobilizer: the engine is being allowed to crank and then denied fuel or spark when the credential check fails. It is a security fault, not a mechanical one, and it is diagnosable on site.
Can you repair the immobilizer without replacing the whole module?
Frequently — antenna rings, wiring and re-registration fix a large share. When a module genuinely has to go, we program the replacement to your VIN in the same visit.
The problem comes and goes — start fine for days, then three failures in a row. What is that?
Intermittent rejection is the signature of a dying key chip, a hairline antenna-ring fracture or corrosion at a connector — heat and vibration make it random. Intermittents are diagnosable; bring us the pattern and we will find the component.
Can a weak car battery really cause immobilizer failures?
Yes — the security handshake happens during the voltage sag of cranking, and a marginal battery drops below the module’s brown-out threshold at exactly that moment. It is the first thing we test because it is the cheapest thing to fix.
After theft damage, my ignition works but the car will not start — what now?
Thieves defeat the mechanical lock and then hit the immobilizer wall — which is it doing its job. We repair the damaged credential path, register fresh keys and deactivate anything the thief touched, restoring both function and security.
Related: key fob programming · transponder keys · all keys lost.
Call (817) 813-8746 — mobile across the whole Metroplex, one all-in quote before we roll.