2009 Mazda RX-8 Key Fob Programming

You can add a new key to this Mazda yourself if you already have two keys that start the engine. The new key must be cut first, and it has to be a genuine key — a cloned hardware-store key won't work.

1. 1Insert one working key and turn it to ON (just shy of starting). Hold it there about 3 seconds, until the security light goes out.
2. 2Turn back to OFF and remove the key.
3. 3Within 10 seconds, insert the second working key and turn to ON. Again wait about 3 seconds until the security light goes out, then turn OFF and remove it.
4. 4Within 20 seconds, insert the new key and turn to ON. Hold for at least 3 seconds, then turn back to OFF.
5. 5The security light comes on for three seconds — that confirms the new key is programmed.

Your 2009 Mazda RX-8 key fob uses a CR1616 3V lithium coin cell. A fresh one typically lasts 3–5 years.

How to replace the battery

1. 1 Slide the release latch and pull the metal emergency key out of the fob.
2. 2 Use that key (or a coin) to pry the two halves apart at the seam.
3. 3 Lift out the old coin cell — note which side faces up.
4. 4 Drop in the new battery the same way (printed + side usually faces the back cover).
5. 5 Press the case back together until it clicks, then test lock/unlock and push-to-start.