Most often it is the key, not the car: a flat smart key cell or a chip that stopped answering. Try your spare first; if it starts the car, a new key is from $125.
The doors unlock, the dash lights up, and then nothing happens, or the engine catches for a second and dies. That pattern means the immobilizer rejected the key. Its whole job is to keep a car from running on a key it does not know.
Every chip key and smart key carries a transponder with a code the car stored at programming. A coil ringing the ignition, or an antenna behind the start button, reads it each time. A car stuck in that state cannot be driven to a dealer either, so their key arrives behind a tow truck, typically $125 to $200. Our pricing has no tow line, because we program where the car sits.
The tell is a key not detected message at the start button, often after weeks of the doors unlocking only up close. Rest the fob flat on the start button, or in the backup slot your manual shows, and press with the brake pedal down. If the engine starts, only the coin cell needs replacing; fob battery replacement covers which one.
The chip is often a glass capsule not much bigger than a grain of rice, seated in the key head. A drop onto a garage floor, years of a heavy ring swinging from the ignition, or a split head taped back together can break or unseat it. The tell: the spare starts the car and this key does not. The car is fine; a new chip key is from $125.
Some kiosks copy the chip's code onto a new key instead of registering a new key with the car. A clone answers with the original's identity, so it relies on the car still trusting that original. After a lost-keys job, a dealer reprogram or a module swap, it can go dark without warning. A key registered as its own entry is the lasting fix.
When no key works, suspect the car. Dim dash lights and a slow, clicking crank mean a weak 12-volt battery that can stop the immobilizer reading any key, so charge it first. Some makes rewrite the key list during a programming session and drop any key not present; a sound remote or smart key can usually be paired again for $79 to $119. We test before selling a key.
If your car is one of these, the make page is the faster read: it names the years, the part that fails and what the repair costs.
Call when the spare works and this key does not, when no key starts the car, or when the light keeps flashing after a fresh fob cell and a charged battery. Tell us the car, what the light does and whether the engine cranks. One price comes back before the van rolls, for a Hillcrest carport the same as a Sorrento Valley office lot.
From the same price sheet as every other job. Confirmed on the phone before we drive.
| Key or job | Typical dealer | Value Car Keys | You keep |
|---|---|---|---|
| Transponder chip key, a working key on handThe working key lets the new one join the car's list, so the $60 all-keys-lost add does not apply. | $125 to $199 | $105 to $181 | |
| Transponder chip key, no key starts the carThe extra $60 pays for programming the immobilizer from blank. Proof of ownership needed: registration or title, plus a matching ID. | $185 to $259 | $45 to $121 | |
| Push-to-start smart keyFor a fob that stays dead with a fresh cell. Add $60 if no working fob is left. | $229 to $399 | $171 to $351 | |
| Pair a remote or smart key the car droppedFor a key in good physical shape that the car no longer lists. | $79 to $119 | $41 to $81 |
Because the immobilizer did not accept the key's chip. On most cars the light blinks while the car is off, which is normal, and goes out a few seconds after a recognized key reaches ON. If it stays lit or keeps flashing at ON, the car refused that key, and the spare tells you whether the key or the car is at fault.
Usually, yes. On many cars the engine fires and the immobilizer shuts it down within a second or two when the chip does not match; on others the starter never turns. Both point at the chip. If a second key starts the car and keeps it running, replace the first key.
On a push-to-start car it can, because the car finds the fob by radio and a flat cell goes silent. Resting the fob on the start button gets around that on most cars, since a reader there wakes the chip directly. On a turn-key car, a dead cell stops the buttons but not the engine.
Often, if the key itself is sound. A car that dropped a key after a programming session or a module swap can learn it again, and for a remote or smart key that is $79 to $119. A cracked chip or a clone gains nothing from reprogramming; a new key with its own entry is the fix.
If no key starts it, yes, since dealer programming happens in their service bay. The truck is typically $125 to $200, and a key the parts counter must order means one to three days without your car. We come to wherever it stopped, and our quoted price already covers the trip.
Guides
Call or text (619) 340-1518 with the car's year, make and model. If a dealer already quoted you, send that quote over for our answer on the same key.