mazda 3 central locking not working

If your Mazda 3’s central locking has gone on strike, don’t panic—start with the cheap fixes before blaming the car’s brain.

• Swap the key fob battery and re-sync; then try the spare key to rule out a tired remote.
• Check the relevant fuses/relays and the car’s 12V battery health—low voltage makes locks act like drama queens.
• Listen for each door’s actuator; no clunk or a sad buzz usually means a failing actuator (common with age)—budget roughly AUD $200–$450 fitted per door.
• Inspect the driver’s door jamb wiring loom under the rubber boot; broken wires or corrosion here can kill the lot.

Less common but possible: a body control module or water-in-a-connector issue—scan for codes before throwing parts at it. If DIY doesn’t cure it, an auto sparky can diagnose for around AUD $100–$200; replacement fobs and actuators sometimes pop up on Tradingpost if you fancy a bargain.