2003 Lexus GX Key Replacement

The 2003–2009 GX uses the same key setup, so everything on this page applies to those years too. The full picture is on the Lexus GX key guide.

2003 Lexus GX: key facts

Key type: Remote-head key
Push-to-start: No
Transponder chip: 4D-68
Programming: OBD
All keys lost: We can originate new keys on site

GX470: 4D-68 remote-head key (HYQ12BBT or HYQ1512V — matched by part number), OBD-programmable including all-keys-lost.

What kind of key does a 2003 Lexus GX use?

The 2003 GX (the GX 470) does not have push-button start. It uses a remote-head key: the metal blade, the transponder chip, and the remote buttons are all built into one head. The chip family on this year is 4D-68. That chip is what lets the engine computer recognize the key, so a blade that merely turns the ignition is not enough. The car also needs to have the key programmed to it.

The remote-head keys for this truck are matched by part number. Two are listed for this setup, HYQ12BBT and HYQ1512V. We check which one fits your vehicle before ordering or cutting anything, because buying the wrong one online is a common way people end up with a key that looks right and will not program.

The vehicle also has a mechanical backup key, which matters if the remote side ever stops working. If the battery in the remote dies, the buttons stop responding, but that is a separate issue from the transponder chip that starts the engine.

Key type: remote-head key, no push-to-start
Transponder chip: 4D-68
Programming method: OBD port
Part numbers: HYQ12BBT or HYQ1512V, matched before we order

Duplicate key or all keys lost: what is the difference on this truck?

If you still have one working key, a duplicate is the simpler job. For this setup an original key is needed to copy from, so bring the one you have rather than waiting until it fails. We cut the blade, then program the new chip and remote to the vehicle.

If every key is gone, the job is still possible. On the 2003 GX, all-keys-lost replacement can be done through the OBD port, and the data we work from says it does not require NASTF SDRM registration. In practice that means we can come to the truck with a mobile van, cut a key from the vehicle's information, and program it on site. You do not need to tow it to a dealer first.

The all-keys-lost route involves more steps than a duplicate, so expect it to take more of the technician's time. It is also the situation where having a spare would have saved you the most trouble.

How we handle a 2003 GX key job

We are a single company with a storefront at 10740 Wilshire Blvd in Westwood and mobile service vans. When you call (213) 577-1366, you reach us directly, not a dispatch middleman. David has run the shop since we opened in 1987 and oversees how this kind of work is done.

Confirm the truck: we ask for the year, model, and VIN, and what keys you have, if any.
Identify the correct key by part number (HYQ12BBT or HYQ1512V) and check it against the vehicle.
Cut the mechanical blade to match the ignition and doors.
Connect to the OBD port and program the 4D-68 transponder to the truck.
Program the remote buttons, then test starting the engine, locking, and unlocking before we finish.

Locked out or need a locksmith now?

We answer around the clock, every day of the year.

Call (213) 577-1366

What affects the cost of replacing a 2003 GX key?

We do not quote numbers on a web page, because the honest answer depends on your situation. These are the things that move the cost:

Duplicate versus all keys lost. Copying from a working key is usually the more economical route.
Where the work happens. A job at our Westwood storefront differs from one at your truck, since the mobile van adds travel.
The condition of the old key. Cracked remote-head shells and worn buttons can sometimes be dealt with by moving the electronics into a new shell, but a fresh key may be the better choice. We look at yours before suggesting either.
Worn ignition wafers. On high-mileage trucks, a worn ignition can make even a good key turn poorly. If that is the cause, replacing the key alone will not fix it, and we tell you that up front.
Number of keys. Programming a second key during the same visit is usually more efficient than coming back later.

What we confirm by VIN before we start

The data for this year is verified, but we still confirm by VIN and in person that the key matches your particular truck, since the two listed part numbers are told apart by checking the vehicle. If anything about your truck does not match what we expect, we will say so plainly and tell you what the alternative is, including if a dealer is the only route. For the broader picture, see our pages on Lexus GX keys, Lexus keys by model, and all car key services. If you would rather write to us first, use the contact page.

Frequently asked questions

Does a 2003 Lexus GX have a push-button start?

No. The 2003 GX uses a remote-head key with a transponder chip, not push-to-start. The chip family is 4D-68.

Can you make a 2003 GX key if I lost all of them?

Yes. All-keys-lost replacement is possible on this setup through the OBD port, and NASTF SDRM access is not required. We confirm the vehicle by VIN first.

Do I need my original key to get a duplicate?

Yes, for a duplicate on this setup an original key is needed to copy from. If you do not have one, we handle it as an all-keys-lost job instead.

Which remote-head key part number fits my GX?

Two part numbers are listed for this setup, HYQ12BBT and HYQ1512V. They are matched by part number, so we check which one belongs with your truck before cutting or programming.

My remote stopped working. Do I need a new key?

Not always. Remote battery failure is a common cause, and it is separate from the transponder chip that lets the engine start. We can check the key before you spend on a replacement.

Should I ask a locksmith for a license before they work on my car key?

Yes. California requires locksmith companies to hold a BSIS LCO license, and you can ask any locksmith for it before work begins.

Can you come to my truck, or do I need to bring it in?

Either works. We have a storefront at 10740 Wilshire Blvd in Los Angeles and mobile service vans. Call (213) 577-1366, answered around the clock, and we will work out which suits your situation.

We cover all these cities

Reviewed by David, Owner & Lead Technician, Wilshire Lock & Key — in the locksmith trade since 1987.

Last updated 2026-10-11.