My partner has a 2010 Hyundai i30 with only 40k miles. She has two keys—both can unlock and lock the car, and both can turn the ignition on and turn over the engine. However, only one key actually starts the engine. The other key almost starts it but always fails.
I’ve already replaced the batteries in both fobs, but the issue persists with one of the keys.
Any thoughts on what could be causing this or any diagnostics I could run?
Cheers!
It sounds like the key with issues might have a problem with the immobilizer chip inside it.
This chip communicates with the car’s computer to allow the engine to start.
Since you’ve already replaced the batteries, the issue likely lies within the key itself.
You could try taking the key to a locksmith specializing in car keys. They might be able to diagnose the problem or even reprogram the key if possible.
If the locksmith can’t help, you might need to visit a Hyundai dealership to have them check the car’s immobilizer system.
It’s possible there’s an issue with the car’s computer rather than the key.
It sounds like the key that fails to start the engine might have an issue with its transponder chip, which is responsible for communicating with the car’s immobilizer system. Even though the key can turn over the engine, if the transponder chip isn’t working properly, the car’s computer won’t recognize it as a valid key, which could be why it almost starts but then fails. Since you’ve already replaced the batteries, it’s not a power issue with the fob. You could try reprogramming the key (if you have access to the necessary equipment), but often this kind of problem requires a visit to a dealership or an automotive locksmith who can test the transponder and reprogram or replace it if needed. It’s worth getting it checked to avoid any unexpected issues down the road. Cheers!
See if there are any instructions on the light remaining on in the owners manual. It is meant to flash if it is unable to identify your key. If it continues to remain on after locking, there may be a problem with the immobilizer. It’s not supposed to do that, in my opinion.