Auto start-stop disable and shows battery charging

Hi everyone, I am new here because I just got a 2023 tundra SR.

Yesterday I had a problem, the auto start top was disable and system shows "battery charging" every time stopped at red light. When the truck move, the message is off (not show all the time).

I did check the battery, it was 12.65 volt when the engine off and 14.1 when is in idle.

The truck was parked all night and today, I check again, the issue is gone, auto-start stop work fine again, but the battery shows 12.55 when engine off (lower than yesterday). When the engine is in idle state, it is still around 14.1.

My tundra is new, it is only 360 miles. I am not sure to bring it to dealer or not. Has anyone seen this issue, or any suggestion?

Also, the battery gauge is not stable, it is moving between 13.. 14.5v (up and down) when I am driving, although fan and ac are same speed. It is not moving a lot, just sometime when I drive, I look at the gauge, it is ~13v, after few minutes, it is 14.5, after few minutes, back to 13v without reason.

The older one we have the battery gauge was always 14v, not annoying as this one.

I don't like auto start-stop feature, I have to press the disabled button when start to drive to disable it temporary. I think the amount of saving gas not enough for replacing the starter, battery or engine, I guess. Any tip/hint to disable it till I want it enable back? I read somewhere seems no way but not sure if I am right.

 

working as designed - I had the same thing happen. If you don't disable and don't press the brake all the way down it won't engage - pressing the brake firmly makes it activate. As you noted you can disable with the button after starting - however once you turn the truck off and restart you must go through the process again to disable by pressing the button. Not what you wanted to hear but so far I've not seen, read or heard of it being permanently deleted from the system.

Edit: @99ways2die has come to the rescue. See below.

 

We have a solution for this already:
https://www.ebay.com/itm/125666096660

 

Hi, thank you guys

My truck is still under warranty so I don't think this is good time to touch electrical, but that will be good solution for the feature.

Any idea with battery charging shown up and gone? As I said above, I don't like this feature so I didn't use it (no hard brake when red light, and press the disable button) so the battery should not be low because of this feature.

I am going to drive the truck for long trip but since it happened, it makes me worry. We need the truck for the trip in next few days, so not sure how long they check, also the issue is gone without any sense.

 

smart idea to not mess with electrical system, and especially when under warranty. I am just gonna stick with the button option. My volt meter on the dash varies too - I think these trucks have a BMS (battery management system) as part of the ECM and it triggers charging. Plus most of the bells and whistles these trucks have are electrically driven - so it would make sense that the voltage is constantly being monitored and adjusted to maintain an acceptable range. I use a SG II and monitor voltage - it usually shows output of 14.1 when under load and much less other times.

 

Just shut that shit off, I hit the button every start up, it’s like on my preflight check list

Truck on, seat belt, auto start stop disabled , Apple CarPlay up and running , check check , ha!

then I don’t worry about that, worst thing on any vehicle and now they all have it

ok, mini rant off

 

Just means you battery needs to charge a bit off the alternator, I notice I get that message more often when the AC is on or if I am doing lots of short trips. Nothing to worry about.

 

LOL. I never have to hit the button. I always have to press a little harder on the brake pedal to activate, so never been a problem. I HAVE been told that I must have got my driver training at the Driving Miss Daisy driving academy.

 

I noticed the battery gauge fluctuating as well. It seems to go down (draw power) when I accelerate, and go up (charge) when I brake. I can't seem to see any other correlation at this point. I have never had a truck with such an active charging gauge!

 

Has anyone had an issue with the start/stop function where it will be activated when stopped at a light and when you let off the brake it makes a terrible crank/clunk noise instead of the normal engine start up? Mine just started doing this and it’s very concerning.

 

I turn that shit off everytime I drive as part of the pre flight checklist

 

Smart charging system for fuel efficiency. The alternator turns off when accelerating/cruising and turns on when decelerating. It also turns on when the voltage gets too low and on first start up.

 

cool, thanks, I was wondering about that too, makes sense

 

LOL - Agreed - Wheels up!