Mazda 6 Forums UK

Technical Section => Vehicle Electrics => Topic started by: Massbad69 on October 06, 2019, 08:58:58 am

Title: Battery change now idle too low
Post by: Massbad69 on October 06, 2019, 08:58:58 am
Hi all

I just changed the battery on my 2009 2.0 petrol Tamura to try and solve the alarm going off intermittently.

Sadly the alarm still has a mind of its own and I’ve no idea what to do now to try and fix it ?

Secondly after the battery change the idle revs are too low and the car stalls at times, tried to reset the ecu but still the same ?

Help
Title: Re: Battery change now idle too low
Post by: apav on October 07, 2019, 03:18:53 pm
I think the alarm is a feature of the second generation car. Some people suggest that it is the spiders tirggering it. If they are not, then you need a very good auto electrician to find a solution.

If your new battery has the same technical specification as the old, you should have not noticed any side effects. I am not sure if the new battery is too big for your car and that triggers a heavy charging mode that needs all this extra power that reduces the idle speed.
Title: Re: Battery change now idle too low
Post by: Massbad69 on October 07, 2019, 06:03:14 pm
I think the alarm is a feature of the second generation car. Some people suggest that it is the spiders tirggering it. If they are not, then you need a very good auto electrician to find a solution.

If your new battery has the same technical specification as the old, you should have not noticed any side effects. I am not sure if the new battery is too big for your car and that triggers a heavy charging mode that needs all this extra power that reduces the idle speed.

Thanks

The battery is slightly more powerful than the standard one but it is correct for the car and recommended.
In the US they recommend a higher power battery as I’ve read a lot of threads on the alarm issue sadly.
The ecu just needs to relearn the idle speed but I don’t know if it takes a while or there is a trick to it
Title: Re: Battery change now idle too low
Post by: apav on October 08, 2019, 11:54:34 am
OK you know better about the bigger battery but be careful not to burn the alternator.

If your bigger battery is never charging, e.g. because the alternator needs ages to charge it and/or you do not drive a lot and/or use it for short drives only, the new bigger battery may last shorter than the right one.