My car won't start and the security light is on — what's wrong?

This is almost always an immobilizer or transponder key issue. The vehicle's ECU is not recognizing your key's security chip. KeySync specializes in immobilizer diagnosis and repair — we come to your location and fix it on the spot. Call 470-540-3370.

I lost all my car keys — can you make a new one without going to the dealer?

Yes. KeySync programs new keys from scratch for virtually any vehicle including all-keys-lost situations. We come to you, program a new key on-site, usually faster and cheaper than a dealership. Call 470-540-3370.

My Toyota Prius hybrid battery warning light is on — do I need to replace the whole battery pack?

Not necessarily. KeySync is a Toyota hybrid battery specialist. We test individual cells and modules to determine if a full replacement is needed or if a targeted repair will solve the problem — saving you thousands compared to dealer pricing.

My car has an electrical gremlin — intermittent issues the shop can't find. Can you help?

Yes. KeySync specializes in deep electrical troubleshooting including intermittent faults, wiring harness damage, corroded connector pins, and module communication failures. We use factory-grade tools including the Wezag LC6 for OEM-quality connector pin repairs.

I replaced my ECU and now my car won't start — what happened?

A replacement ECU needs to be programmed and coded to your specific vehicle VIN and security system. KeySync performs ECU cloning and coding — we can clone your original ECU data to the new unit or program it from scratch.

Can you repair wiring without replacing the whole harness?

Yes. KeySync performs factory-style wiring harness repairs using the Wezag LC6 crimping tool, creating OEM-quality connector pin replacements — saving you the cost of full harness replacement.

Where is KeySync located and what areas do you serve?

KeySync is based in Woodstock, GA and provides mobile service throughout Cherokee and Cobb counties including Marietta, Canton, Kennesaw, Alpharetta, Roswell, Holly Springs, Acworth, Smyrna, and Ball Ground. We come to you.

How much does car key programming cost?

Key programming pricing depends on your vehicle make, model, year, and key type. Basic transponder keys typically start around $150. Use our VIN estimator at keysync.net or call 470-540-3370 for an accurate quote.

KeySync Locksmith & Programming | ECU/TCU, Key Programming, Wiring Repair & Toyota Hybrid Specialist

The Specialist for Problems Other Shops Can't Solve

Deep electrical troubleshooting, ECU/TCU programming & cloning, factory-style wiring harness repair, key programming, and Toyota hybrid battery diagnostics — we come to you, anywhere in North Georgia.

Mobile service — we come to you

All makes & models

Advanced diagnostics

Serving Cherokee & Cobb counties

Key Programming

"I Lost All My Car Keys — The Dealer Wants $800 and a 2-Week Wait"

This is one of the most stressful situations a driver faces. Your car is sitting in your driveway — perfectly fine — and you're completely locked out of your life. The dealer's timeline doesn't care about your job, your kids, or your schedule.

The reality is that all-keys-lost programming requires the right equipment and the right knowledge — not a dealership franchise. KeySync carries professional-grade key programming tools that work on virtually every make and model. We come to your location, program a new working key directly to your vehicle's immobilizer system, and you're driving again — usually the same day.

What we actually do: We connect to your vehicle's OBD port, read the immobilizer data, generate a new key with a matched transponder chip, and program it live. No towing, no waiting, no dealer markup.

Call for Same-Day Key Programming

Electrical Repair

"Three Shops Couldn't Find the Problem. My Car Still Has Random Electrical Gremlins."

Intermittent electrical faults are the nightmare of modern vehicles. The car throws a code, the shop clears it, a week later it's back. Or worse — it never throws a code at all but something is clearly wrong.

Most general repair shops are not equipped for deep electrical diagnosis. They scan codes, replace the part the code points to, and call it done. But faults caused by damaged wiring, corroded connector pins, or a failing module don't always leave an obvious trail.

What makes us different: We trace circuits, test signal integrity, and inspect connector pins physically. When we find damaged wiring, we don't just splice — we use the Wezag LC6 to install factory-style crimped connector pins, restoring the connection to OEM spec. No more band-aids.

Call for Electrical Diagnosis

Toyota Hybrid

"My Prius Has a Red Triangle Warning Light — The Dealer Quoted Me $4,000 for a New Hybrid Battery"

That red triangle of death on a Toyota hybrid sends most owners into a panic — and straight to a dealer quote that starts at $3,000–$5,000. But here's what most people don't know: in the majority of cases, the entire battery pack doesn't need to be replaced.

Toyota hybrid battery packs are made up of individual modules. When one or two modules fail, the whole pack triggers a fault. A specialist who can test at the module level can often repair or replace only the failing cells — bringing your battery back to full function at a fraction of dealer cost.

Our approach: We test every module individually, identify exactly what's failing, and give you an honest assessment. Prius, Camry Hybrid, Highlander Hybrid, RAV4 Hybrid — we work on all Toyota hybrid platforms.

Get a Hybrid Battery Assessment

ECU Programming

"I Bought a Used ECU Online to Save Money — Now My Car Won't Start at All"

It's a trap thousands of car owners fall into every year. A replacement ECU from eBay or a salvage yard looks like a $200 fix — until you install it and discover the car won't start, the immobilizer rejects it, and now you're worse off than before.

Every ECU is married to a specific vehicle through VIN coding and immobilizer pairing. A used unit from a different vehicle needs to be reprogrammed before your car will accept it. This requires professional dealer-level or better software — not a generic OBD scanner.

What we can do: We can clone your original ECU's data onto the replacement unit, or perform a full virgin programming sequence. We also handle TCU (transmission control unit) programming and adaptation resets after replacement.

Call for ECU Programming Help

The Specialist for Problems Other Shops Can't Solve

Specialist Automotive Electrical & Programming Services

Deep Electrical Troubleshooting

Wiring Harness & Connector Pin Repair

ECU/TCU Programming, Coding & Cloning

Toyota Hybrid Battery Specialist

Key Programming & All-Keys-Lost

Immobilizer Repair & Module Reset

Get a VIN-Based Quote

Mobile Service Area

Book Mobile Service

Common Problems We Solve Every Day

"I Lost All My Car Keys — The Dealer Wants $800 and a 2-Week Wait"

"Three Shops Couldn't Find the Problem. My Car Still Has Random Electrical Gremlins."

"My Prius Has a Red Triangle Warning Light — The Dealer Quoted Me $4,000 for a New Hybrid Battery"

"I Bought a Used ECU Online to Save Money — Now My Car Won't Start at All"

Frequently Asked Questions