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Drew, Super Mazda Tech.
Category: Mazda
Satisfied Customers: 2518
Experience:  19 yrs. experience. Mazda Senior Certified Tech, with Ford, Linc. & Merc. experience. ASE L1 Advanced Certified Master Tech.
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My keyless entry system stopped working..doors..lock/unlock..spare

Resolved Question:

My keyless entry system stopped working as of yesterday.
I see red lights flashing on the remote whenever I press the buttons, but the doors would not lock/unlock so I had to use the actual key to lock/unlock it.
I tried my spare one but it still did not work.

I own a Mazda6, 2006 hatchback sedan.
Submitted: 5 years ago.
Category: Mazda
Expert:  Drew replied 5 years ago.

Welcome to Just Answer. My name is XXXXX XXXXX I will be glad to assist you.


Start by checking the 15A room fuse. Replace if blown. #4 in diagram.


If the fuse is good, check to see if the power locks will lock/unlock from inside the car using the drivers master switch.

If your concern is still present, let me know and I will get you the next diagnosis steps. Simply hit the reply button.





Customer: replied 5 years ago.
I checked the specified fuse and did replace it with a new one, but it still doesn't work. Also, the door lock does work from the driver's side.
Expert:  Drew replied 5 years ago.

Since the power locks operate from the master switch, that indicates the system is operational. Your next step will be to replace the battery in the transmitters.


Let me know if this does not resolve your concern and I will give you the next step.

For your next reply I will need to know if you have factory keyless entry (switch blade key) or advanced keyless entry (smart card)


Also is there is any aftermarket alarm/remote start system installed, REMOVE it.



Customer: replied 5 years ago.
Sorry it took so long to reply!
It took me some time to replace the battery and actually test it out.

I replaced the batteries on the remote but it still didn't work...

I do have a factory keyless entry with switch blade key. There is not aftermarket alarm/remote system installed.
Expert:  Drew replied 5 years ago.

Now that I know you have the switch blade key, I suspect that you have a faulty BCM (body control module)


This module is located in the left front foot kick panel area. Check to see if there is any sign of water or wet carpet on the drivers side. I have seen water leak into the BCM module and cause this concern. (#4 in diagram)


Next remove all connections the the BCM and check for corrosion, water or damage to the module.


If all looks good, I want you to try to program the transmitter key fob. Here is the procedure. Try several times.


Verify that door locks cycle to the lock/unlock position when entering the programming procedure.


Let me know.







  1. Disconnect the negative battery cable.
  2. Remove the front side trim. (Left side)
  3. Remove the fuse block.



  1. Remove in the order indicated in the table.
  2. Install in the reverse order of removal.


Key transmitter programming.




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