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2016 Mazda6 Multiple Warnings after Battery Disconnect, Help!

Hi, today I decided to reset the istop by disconnecting the battery.

I normally do this occasionally to get the istop running.

However on this occasion, the car threw up the following sign. I tried battery disconnection for about 20 minutes by disconnecting the negative terminal.

Before I take it to the dealers who will no doubt charge an arm and a leg, is there anything else I could try before surrender to the dealership.

Perhaps the alternator has packed in, or maybe the software needs resetting?

Anyone had this similar experience?
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Forgot to mention, the a/c fans, indicator lights, hazard lights also stopped functioning.

I wonder if it's gone into limo mode? How do reset?

I plugged in my Autel code reader but no solid codes found.

The car battery seems to be reading 12.9v, and I've not put it on trickle charge.
 
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Ottawa, Ontario
:
17 Mazda 6 GT
Where are you located? I didn't think Mazda had Istop in North America.
It's definitely not a feature in any Mazda vehicle in Canada.
Also: what year and model is your Mazda?
 
Hi, I'm based in UK. It's a Mazda 6 2016, I think its referred to as GL model. 2.0 skyactiv petrol engine 165bhp.
 
Someone else also mentioned about the battery. I did connect it to smart charger, its reading 12.9v with load. Hope its within the acceptable range?

I have placed an order on ebay for second hand current sensor which is on its way. I found out that the part number is the same across most Mazdas with I loop. The one I have on its way was removed from a salvage Mazda CX. Part no. 6PK 010.575 -50

If it works it will be a cheap DIY fix and save a trip to the dealership.
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:
Ottawa, Ontario
:
17 Mazda 6 GT
Hi, I'm based in UK. It's a Mazda 6 2016, I think its referred to as GL model. 2.0 skyactiv petrol engine 165bhp.
OK, I didn't know that Mazda even offered the smaller engine in a 6, like, anywhere.
Here in Canada (and the U.S. I believe), it only came with the 2.5 N/A engine, until 2018 when the 2.5 turbo became available. Also, we don't have stop/start here thankfully.
Don't take this the wrong way, but driving my 2017 Mazda 6 with the non turbo 2.5, I can't imagine downgrading to a 2.0 with only 165hp.
Anyway, keep us posted if you fix the problem.
 
We have 2.0 and 2.5litre engine without the turbo. We also have diesel engine variants, sorry I don't know the size.

Anyway, just an update regarding my problem. I swapped out the current sensor with no joy 😞

Anyways, I did another battery test and I got the following screen. I performed the test twice and the readings are shown below.

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I have put the battery back on charge to see if it makes any difference. The car does start though but the dash remains lit with warning lights.
 
Booked in with Mazda dealership, my standard Autel Maxi Check could not detect any codes so a trip to the dealer is imminent. Will update
 
Forgot to mention, it not the battery, have replaced it with a new stop start Varta battery, 630cc, which has slightly higher cranking value over stock Panasonic battery at 520cc.
 
Okay, got some good news. The car is now fixed. I apparently fried the BCM whilst performing the battery reset. I have no idea how it got fried but that's what it was. I took the car to Mazda dealership to run me a diagnostic, confirming a faulty BCM.

The car is now running fine, no problems. The BCM is actually easy to replace, only took me 5 minutes. Its housed inside the fuse box any anyone can replace it, no previous experience required, only need flat screw driver to release the clips to remove the unit which slides out. Even the plugs are colour coordinated so can't go wrong.

I hope this thread is useful to someone. If you experience the same symptoms, it may need a BCM. The part I installed is second hand and taken out from a Mazda CX5. The part numbers must match for it to work but please check on, the numbers sometimes are superceded and usually denoted by a minor change to the last character. For example my original part number is TK52-675X0B, which was later only available as TK52-675X0C.

Anyways, happy days. 😊
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Hi apologies, the BCM stands for body control module, it's controls some of functions like Istop, smart city brake assist, interior fan heater/AC, wipers, indicator/hazard lights. These were all the items which were knocked out when I fried it.

Thankfully I found a cheap replacement from ebay, a secondhand item from a CX5. The BCM is found inside the fuse compartment box, it's rather expensive from the dealership, so was lucky to have found it.