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Crenshaw Lock

Transponder Key Programming in Monrovia · 24/7 mobile

Transponder Key Programming in Monrovia, California

Crenshaw Lock Company provides mobile transponder key programming in Monrovia, California, 24/7. We come to your car and program chip keys to its immobilizer, whether you lost your only key or want a spare. Call (323) 997-8867 to talk through your vehicle and get started.

  • Mobile to your Monrovia location
  • Available 24/7
  • Price quoted before we start
Call (323) 997-8867or tap to call — we answer 24/7
Car key being programmed with a handheld programmer inside a car
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Most cars built since the late 1990s will not start with a plain metal key. Inside the plastic head of the key is a small transponder chip, and the car's immobilizer checks that chip before it lets the engine run. If the chip is missing, blank, or unregistered, the engine may crank without firing, or it may not crank at all. Transponder key programming is the work of teaching the car to recognize a new key.

In Monrovia, this comes up in everyday ways. A commuter parks at the Metro A Line station and loses a key before heading home. A family on a hillside street above Foothill Boulevard realizes they have only one working key for a car that gets used daily. Someone buys a used car and gets handed a single key with no spare. Each of these is a situation where waiting for a tow and a dealer visit can be avoidable.

Crenshaw Lock Company has served Greater Los Angeles and Ventura County since 1987, and we are fully mobile. There is no shop to drive to. We bring the equipment to your driveway, a curb in Old Town, or a parking lot, and we are available around the clock. Owner and lead technician David Shar and our team handle the programming on site, so you are not left stranded while you figure out the next step.

How it works in Monrovia

  1. 1

    Call and describe the vehicle

    Phone (323) 997-8867 and tell us the make, model, and year, and whether you still have a working key. That tells us whether this is a spare-key job or an all-keys-lost situation, which changes the approach.

  2. 2

    We come to your location

    We are mobile only, so we travel to you, whether that is a home near Library Park, a street in Mayflower Village, or a lot along Huntington Drive. We do not give arrival-time promises, but we do work 24/7.

  3. 3

    Confirm ownership and vehicle details

    Before cutting or programming anything, we verify that you are the owner or authorized user of the vehicle. This protects you and is a normal part of responsible automotive locksmith work.

  4. 4

    Cut or prepare the key

    If the key needs a blade, we cut it to match your vehicle's lock. If you already have a compatible transponder key or fob, we check that it is suitable and ready to be registered.

  5. 5

    Program the chip to the immobilizer

    We connect programming equipment to the car and register the new key so the immobilizer accepts it. Depending on the vehicle, older keys may be kept or cleared from the system.

  6. 6

    Test every function

    We confirm the key starts the engine, turns the ignition, and operates the door locks. If remote buttons are part of the key, we test them before we call the job finished.

Need transponder key programming in Monrovia?

24/7 Mobile Locksmith across Greater Los Angeles & Ventura County. We answer 24/7.

Call (323) 997-8867

What affects the price

  • Make, model, and year of the vehicle, since some immobilizer systems are more involved to program than others.
  • Whether you have a working key already (adding a spare) or have lost every key and the system must be programmed from scratch.
  • The type of key: a basic transponder chip key, a flip key, a remote head key, or a push-button smart key each involve different parts.
  • Whether the key blade needs to be cut, including laser-cut or high-security profiles.
  • Time of day and location, since we work 24/7 and travel to you throughout the area.
  • How many keys you want programmed in the same visit.

Why Monrovia chooses us

  • Fully mobile service: the equipment comes to your car in Monrovia, so you never have to tow a vehicle to a shop that does not exist.
  • In business since 1987, which means decades of experience with changing key and immobilizer technology.
  • Available 24/7, so a lost key at night after dinner on Myrtle Avenue does not have to wait until morning.
  • One company for cars, homes, and businesses, so we can also handle the house locks and gate hardware if you need them.
  • Honest guidance on whether you need a new key, a spare, or simply a repair, without pushing unnecessary work.
  • Ownership verification on every job, which protects you from key-related theft.

Transponder Key Programming across Monrovia

Monrovia is a foothill city where cars are part of daily life. Residents drive I-210 (the Foothill Freeway) to work, take Myrtle Avenue and Huntington Drive for errands, and climb Mountain Avenue toward the canyon. Old Town Monrovia brings visitors and diners to Myrtle Avenue and the Aztec Hotel, and the Metro A Line station draws commuters who leave cars parked for the day. A lost or damaged key in any of these places can leave you stuck.

We work throughout the city, including ZIP codes 91016 and 91017. In Old Town, we can meet you at a curb or in a lot near Library Park. In Mayflower Village, we program keys in the driveway of your home. In North Monrovia, the foothill streets above Foothill Boulevard often have long driveways and tight turns, so tell us where the car is parked and we will plan accordingly. Hikers heading to Monrovia Canyon Park occasionally lose keys on the trail, and we can help when you return to a car that will not start with a replacement.

Because we are not a storefront, your car does not have to move. If you are already thinking about locks at home, such as the original hardware on an Old Town Craftsman or the gate locks on a hillside lot, we can look at those during the same visit. Call (323) 997-8867 any time, day or night.

Locked out or need a locksmith now?

24/7 Mobile Locksmith across Greater Los Angeles & Ventura County. We answer 24/7.

Call (323) 997-8867

Other Monrovia locksmith services

See all of our Monrovia services, or our citywide transponder key programming page.

Transponder Key Programming in Monrovia — FAQs

What is transponder key programming?
It is the process of registering a key's embedded chip with your vehicle's immobilizer so the car recognizes the key and allows the engine to start. Without programming, a key that fits the ignition may still not start the car.
Can you program a key in Monrovia if I lost all my keys?
In many cases, yes. All-keys-lost situations are more involved than adding a spare, but we handle them on site depending on the vehicle. Call (323) 997-8867 with your make, model, and year.
Do I need to tow my car to you?
No. We are fully mobile and come to your car in Monrovia, whether it is at home, in Old Town, or at a parking lot. There is no storefront to visit.
Are you available at night and on weekends?
Yes. We are available 24/7. Call (323) 997-8867 any time and we will talk through your situation.
What affects the cost of programming a transponder key?
The main factors are the vehicle, the type of key, whether you have a working key, whether the blade must be cut, and how many keys you need. We do not quote prices on this page, but we can discuss your specific situation by phone.
Is it cheaper to just add a spare key before I lose the only one?
Generally, adding a spare while you still have a working key is simpler than recovering from all keys lost. It is worth doing, especially for a daily-driver car.
Do I need to prove I own the car?
Yes. We verify ownership or authorization before programming, which is standard practice and keeps your vehicle secure.
Can you also help with home or business locks in Monrovia?
Yes. Besides automotive work, we handle residential and commercial locks, including rekeying older Craftsman hardware and Old Town storefront locks. Call (323) 997-8867 to ask.
DS

Reviewed by David Shar — Owner & Lead Technician

Crenshaw Lock Company has served Greater Los Angeles & Ventura County since 1987.

Last updated 2026-10-12.

Call (323) 997-8867 · Open 24/7