Hello,

I am looking for help with my 2013 Mazda 3. It has the 2.0 with a G engine ID in the vin. The issue I have is that while driving at 60mph and 3k rpm the battery light comes on. I will also get the Traction Control and ABS warning light solid on. Soon after or at higher rpm I will also lose Power Steering and I get the indicator for that as well and the Emergency Brake light comes on. I can see that the headlights dim. Once I bring the RPMs down the warning lights go out except for the Power Steering until the speed and RPM come down.

I have replaced the battery and plan to test/replace the alternator next. Is it as simple as a bad alternator? But why would it loose function at high rpm and not low rpm?

I appreciate any thoughts or advice.

 

Welcome to the forum

The first things to be asked is what if any DTC(s) did you get? Even if the check engine light is not on you should check it directly connecting to the OBDII diagnostic connector with a scan tool. Based on what you posted you should have gotten between 1-3 DTC min.

Why did you change the battery.

Did you load test both the old as well your new battery.
It would have been a better idea to have checked the charging rate output of the alternator before changing that battery. However, that is now an important check to do now.

You should also look at the battery leads at the starter and all the ground. The battery is only part of the cables making good contact.

The higher the RPM the more demand is on the ignition system so naturally if the supply voltage and amps is not there your power will suffer.

 

Thank you for the guidance, I will check to see if there are any codes. I didn't know there could be codes if the light was not on. The reason I changed the battery was that it was the original battery that was in the car when I purchased it in 2019, and has a 2016 manufacture sticker on it, so I assumed it was the problem. I will have the alternator tested for charge rate.

 

Your correct about not having any codes related to your issue if the "money light" never came on. Kind of a waste of time but cant hurt anything. And I would have replaced that battery also, get that variable out of the equation. If you have a meter that checks AC Voltage you can put the leads on the battery while its running. If you have a bad diode in the alternator you could see from 1 to 30 VAC on that batt. Batteries don't like ac voltage. Thats going to trip a fault. But its also going to show as a parasitic drain on your battery. But that's not going to show up unless you let your car sits for three or four or five days. So check for AC volts, and check for a parasitic draw no greater than 20 to 40 milliamps. You wont find any DTCs

 

.. . YES, you would have likely generated a DTC(s) or monitors possibly in fault. And DIY and mechanics should not replace parts when there is a current unresolved or before you first check out what caused the problem. And yes, you should load test the battery you are replacing as well the ne battery you buy.
Replacing parts at random before verifying they are an issue related concern many times causes added problems or simply wastes you time and money. When the OBDII and CAN-bus was standardized, it actually made diagnosis most problems easier. But this does require to have some experience and better yet training!
Maybe someone is watching Life Below Zero too much. LOL
I

 

Thank you all for you input and suggestions. The alternator was bad. I took it into the store and they found it only outputting 11amps, with 13 being minimum acceptable for my system. Main take away that I have learned form this is test before throwing parts at the problem. Really appreciate you all taking time to contribute.

 

Thanks for returning to your thread with the results. It is alway appreciated! Glad to hear the MAZDA is all fit and up and running for you well again.