marekEU

Hello,

In last few days I have small problem using start/stop system in my 200t IS. When I stop the car on lights and system should auto turn off engine I get the message as in pic below (Non-dedicated battery"). Engine keeps running. It doesnt show any other messages as before - about battery recharging or air-condition running etc. For me it looks like some iisue with battery. I'm currently in Spain where 200t is not offered - they have only hybrids so lack of experience with specific 200t issues. Dealer check battery and it seems to be fine. They are trying to figure out what it can be.

Maybe anyone here had similar issue or know what could be source of it?

https://ibb.co/d8D33G

specONE

iTrader: (3)

Sorry but you are on your own there. In North America, Lexus vehicles do not have this Auto start and engine stopping feature when idling at Stop light/signs
We wouldn't be able to really comment about this feature.
There is not many European members on here as well.

marekEU

Seems like you are lucky having cars without it
I just found in instruction that it means that Battery is "not compatible" with this auto start/stop system. It seems like they will have to replace it.
Hope it will help someone in future

Machine13

I think that most cars that have auto start/stop feature also have a secondary "Auxiliary" battery. In my MB E350, this auxiliary battery is smaller and it's located in the trunk by the spare tire. In other cars the auxiliary battery may be located under the dash or elsewhere in the cabin.

The auxiliary battery has a few purposes; to provide isolation from draining the engine's battery; to provide power to cabin electronics while engine is off; and possibly to provide extra oomph to the starter to get the engine back up to speed quickly when driving off from a stop.

Considering that the auxiliary battery is used kind of like a safety feature as a way to isolate the main engine battery from getting drained while you're on the road, it makes sense that your car would protect itself by not even going into eco start/stop mode unless this auxiliary battery was both present and functioning correctly.

As a matter of fact, I just had to change my auxiliary battery in my E350 because it wasn't holding sufficient voltage. While this battery malfunction was occurring the E350 wouldn't allow itself to auto stop the engine. It just kept running.

I'd recommend finding out if your auto start/stop feature requires an auxiliary battery, where it is located in the cabin, and test whether it's providing voltage correctly.

Based no the message you are receiving, it appears to me this auxiliary battery is missing from your car, or undetected.

marekEU

Hey Machine13, that's very good point! That would explain why battery was fine by dealer. They have checked only main battery, since they are not familiar with this system having only hybrids in Spain.

Machine13

Exactly! I hope it's as simple as that. Keep us posted please on what the resolution was.

marekEU

I will, thanks for a tip!

marekEU

In final service replaced main battery under warranty. Since then everything is perfect again.