New Aux battery, ESS light now on, can't clear

[KQL]

If the start/stop could have been implemented without the added cost of an Aux battery, I bet they would have done it in a heartbeat. Good to hear there have been no complications, but there must be some scenario that 1 battery can’t support?

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[Mr._Bill]

The purpose of the Aux Battery is to keep the computers stable during the ESS restart. The batteries are paralleled together all the time, except during the startup test for the Aux Battery and during the ESS restart. The system will operate normally on one battery, until the battery reaches a point where the high draw from the starter drops the system voltage below the level acceptable to the computers.

 

[Sixt7gt350]

Getting ready to go out to check individual voltages and check fuses.
Other than F42, which fuses are related to this abominable ESS system?

Found the fuse array, every position tested fine with the meter.
Both batteries resting at 13.1V
IBS has been disconnected all morning.
Gonna give both batteries a topoff, then put everything back together.
With the weather letting up, maybe not remote starting will make a difference for IBS learning.

 

[Sixt7gt350]

Found the fuse array, every position tested fine with the meter.
Both batteries resting at 13.1V
IBS has been disconnected all morning.
Gonna give both batteries a topoff, then put everything back together.
With the weather letting up, maybe not remote starting will make a difference for IBS learning.

Everything back together and buttoned up. No ESS light, stop/start "ready."
Tested stop/start at the end of my driveway, worked fine.

I made sure to reconnect the main immediately after connecting the aux.
Last time, aux was alone while I put the fender liner and mudflap back in place, so it's possible that the normal dark current took it down just enough to throw things off.

With OBD watching voltage, the seat, back window, and steering wheel heaters that come on with remote start below freezing, it drops from 14.8 to 14.6 volts. Shouldn't be enough to kill a battery, but info to share.

Thanks for everyone's input.
Here's hoping for 5 years before having to buy $300+ of batteries again.

 

[Lost1wing]

Found the fuse array, every position tested fine with the meter.
Both batteries resting at 13.1V
IBS has been disconnected all morning.
Gonna give both batteries a topoff, then put everything back together.
With the weather letting up, maybe not remote starting will make a difference for IBS learning.

You will have had to isolate the terminals to properly test the fuse array, just to be sure your continuity is through the fuse and not backfed through the vehichle

I made sure to reconnect the main immediately after connecting the aux.
Last time, aux was alone while I put the fender liner and mudflap back in place, so it's possible that the normal dark current took it down just enough to throw things off.

Definitely, it will throw things off. Disconnecting the fender ground wire first and reconnecting it last is the way I would do it.

I'm glad you have it back together and worki g as it should. Some icons may not be present right away. Give it a day or so.

 

[Minty JL]

2019 on OG batteries........time to replace

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