TextHow the Century Key System Has Evolved
Early W-Body Transponder
Theft prevention got real on the Century with this generation. The 1997-1999 build slips a Texas 4D (ID44T) glass capsule into the plastic key head, and that capsule has to satisfy the VATS/Pass-Key III immobilizer before the starter fires. No remote buttons on the key itself; lock and unlock live on a separate keychain fob.
Remote Head Key Arrives
Model years 2000-2002 collapsed two pieces of plastic into one. The same Texas 4D (ID44T) chip still does the immobilizer handshake, the same Pass-Key III still gates the engine, but the lock, unlock, and trunk buttons now share the same molded head as the blade. One keychain item to track, one to replace when something goes sideways.
Late W-Body Refinement
Final Century years standardized the integrated remote head key across the lineup. Texas 4D (ID44T) inside, Pass-Key III on the BCM side, factory remote keyless entry baked in from the spec sheet. Programming still leans on OBD-II port access with a security PIN read, which the Autel IM608 pulls from your BCM in your Carmel Valley driveway.
Which Century Fob Are You Holding?
Standalone transponder blade with a thick plastic head hiding the Texas 4D chip. Your remote fob is a separate piece living elsewhere on your keychain.
Everything consolidated into one molded piece. Lock, unlock, trunk buttons share the head with the transponder chip. Single item to carry, single item to replace if it fails.
Carries the 2000-2002 remote head design into the final Century years. Three buttons, standard cut blade, Texas 4D chip riding inside. Factory remote keyless entry shipped on every trim by this point.
Century Key Pricing by Generation
Every quote bundles the blank, the cut, the transponder pairing, and the remote sync. What we say on the phone is what hits the receipt in your driveway.
EZ Car Keyz vs. the San Diego Buick Dealer
We carry the exact same factory-grade programming platforms the San Diego Buick dealer relies on. Difference is the van pulls up to your house and the bill lands at roughly half what the dealer counter would write.
Skip the Dealer - Call (619) 876-1271Common Buick Century Key Failures
Transponder Chip Failure
After two decades of pocket cycles, the Texas 4D capsule in your Century key quits talking to the Pass-Key III module. Engine cranks but refuses to fire. Marco bench-tests with a Tag Probe, then cuts a fresh transponder blade if needed.
Key Fob Battery Drain
Dead fob? First move is the CR2032 and a contact cleaning. Coronado and Imperial Beach humidity eats the brass contacts inside the remote head, and corrosion kills more Century fobs than circuit failure does. Three-dollar battery plus a polish.
Ignition Cylinder Wear
First crank nothing, second try fires, third dead silence. This intermittent dance on a high-mile Century is almost always the cylinder past spec or the Passlock sensor losing calibration. Marco scopes cylinder and sensor separately.
Immobilizer ECM Fault
A 2003-2005 Century throwing a false security lockout is rarely a key problem. The BCM loses comm with the transponder reader, mimicking a dead chip. Marco pulls BCM codes first; a third of these calls resolve with a module reset, no new key.
Can You Self-Program a Century Key at Home?
Yes for the remote half. The door unlock switch method pairs the lock and unlock buttons on your fob to the receiver without any tools. What it does not touch is the Texas 4D transponder chip that authorizes the starter; that side still needs an OBD locksmith for the BCM PIN read.
Yes for remote pairing, no for the transponder. Ignition cycle drill: rotate the key ON, OFF, ON, then crack the driver door and hold lock plus unlock until you hear two chimes. That binds the buttons. The chip handshake to Pass-Key III still needs professional kit.
With at least one working Century key already in your hand, GM's ten-minute relearn lets you add a fresh transponder. Drill: working key in, rotate ON, pull within ten seconds, slide the new blade in, watch the security telltale. Timing is unforgiving, and the new key must already be cut to your ignition pattern.
Zero DIY path on all-keys-lost. The cycle requires an OBD interface, a BCM PIN read, and professional software to write the chip to the immobilizer. (619) 876-1271 and Marco brings the kit to your car.
How It Works
Ring the 619 First
Dial (619) 876-1271 with the model year handy and a quick description of what failed.
Marco Rolls the Van
San Diego County wide, La Jolla north through Oceanside, Coronado east through Alpine.
Cut and Pair at the Curb
Blade gets cut on the van using a GM-standard cutter, then the Texas 4D chip rides through the OBD-II port via Autel IM608 into your Pass-Key III immobilizer.
Related Services
Buick Trivia
Here is a small piece of GM trivia: the 1997-2005 Century earned the distinction of being the last W-body sedan to keep a true six-passenger front bench seat on the spec sheet. While the rest of GM marched the lineup toward bucket seats and tall center consoles, Buick refused to ditch the bench because the customer base genuinely wanted it. Quiet rebellion against the sport sedan tide, and it paid off in repeat family-buyer loyalty.
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