Mazda 2 2011 - Battery light on, battery & alternator working

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Mon 7 Oct 2019 19:26
Mazda 2 2011 - Battery light on, battery & alternator working - Brodie Ross

Hi there,

I just recently bought a Mazda 2 from a private seller and after a few weeks of use the battery charging light has come on. I tested the voltages across the battery and alternator and they were both fine (12.3v and 14.5v respectively). I also checked the majority of the fuses in the car which were also fine. I then took the Car to an auto electrician who advised that there was electrically nothing wrong with the car and it was likely a computer issue. He said I could take the car to a Mazda dealer to get diagnostics run but that this would likely be expensive so he didn't recommend it.

I'd tend to agree with him but I thought it would be best to get a second opinion before resigning myself to having a little red light on my dash haunting me. Any advice would be much appreciated.

(Also worth noting I had to replace the battery shortly after buying the car, could this affect anything?)

Cheers,

Brodie

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Mon 7 Oct 2019 23:03
Mazda 2 2011 - Battery light on, battery & alternator working - elekie&a/c doctor

The alternator and battery charge and warning light are controlled from the engine ecu. May be an idea to get a diagnostic done on the engine system, just in case there is an issue here. Also try a battery disconnect for 5 mins ,just in case there is an electrical glitch in the system.

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Wed 9 Oct 2019 05:14
Mazda 2 2011 - Battery light on, battery & alternator working - edlithgow

I get that too, but intermittantly, as in, "intermittant fault".

Pretty sure an ECU is not involved in my case, since I don't have one.

This is nice, but evidently things can still go wrong even without an ECU.

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