Morning,

I've had ongoing issues with my battery going flat. I've had the car 3.5 years and am on my 3rd battery. Until recently, no-one has been able to find any draws on the battery that could be causing the battery to go flat.

I've just had it with my 3rd Auto Electrician and they've diagnosed a fault with the Body Control Module (BCM). This has been replaced and now only drawing 0.01amps when car is off. However, after replacing the BCM, the radio controls on the steering wheel don't work, the GPS doesn't work and the Reversing camera doesn't work. This is an after market stereo so has always been my concern that this has been causing my issue but no-one has been able to say for sure yes or no.

How do you test/know that a BCM is having issues? How do you know that draw on the battery is resolved if everything that was connected is no longer connected. Would the 3 things that aren't working normally be connected/controlled by the BCM?

My concern now is that once these items get connected again, I'll back to square one with a battery drain.

Any help/advice would be greatly appreciated.

Cheers,
Frustrated Owner!

 

Kia ora bro.

The BCM is basically a new generation fuse box, with inbuilt relays. Most of the circuits in the car will get their power from, or run thru the BCM. The drain may or may not of been directly from the BCM, it could've been a circuit running thru it.

To check for drain, you disconnect the battery, place a amp meter between the battery lead & battery terminal, then you start pulling fuses 1 by 1 to see which circuit is causing the drain.

 

Hi there, I’m having an issue similiar by the sounds of it. Can you please explain the issue that was happening to your car before it got diagnosed? I have taken it to an auto sparky three times and had two new batteries but we don’t know what’s wrong with it...
I also have a Mazda atenza 2006