CAR completely DEAD ?

[Wlepse]

When all this crap settles down I will have to bring it back in to have them look at it, if I could get 5 weeks I would be OK with that. I might even be able to deal with 2 weeks, but what is more troublesome is when one time 2 weeks is ok then another time 4 days is too much.

 

[Hunter Mike]

I believe this ties back to the BCM. It is my understanding that the BCM monitors voltages/resistance in each circuit. If it finds something amiss, it disables the ASS to protect the battery and leave the car in a position to not strand the driver. I believe that it continues to monitor even at rest when there is a circuit amiss. So if you change one bulb to an LED, it will scrutinize that circuit until a properly rated incandescent or halogen is installed(or you trick the BCM with a resistor or specially designed device) and circuit returns to the expected design criteria.

All of the modules are linked in a controlled area network so it one module is misbehaving it can cause a communication error with all the other modules in the line. Every one of these modules can store trouble codes so it can be read by pro-level scan tools. If it’s not an emission code, it won’t illuminate the MIL. I bet you have a problem because your battery went dead and some PID didn’t like it. See if this leads you down the right rabbit hole:

State-Of-Charge And Charging Systems Diagnostics On Late-Model GM Vehicles

 

[Wlepse]

The app I have does read beyond engine codes, though I don't know how deep it goes into specific BCM's. I do see in the main screen it includes ABS, trans, SRS and PCM as well as OBD codes. I have had other codes thrown but they all seemed to be error codes from the voltage being too low.

Reading through that info is interesting but in the first section it states that it will monitor the system and display an alert in the DIC if a problem is detected. For me this NEVER happens. Would be interesting to see if others who are having this issue get any warnings and if so what they say. I have gotten emailed warnings from Onstar after the fact that my voltage was too low and there were other trouble codes, but never prior to the battery failure.

Also it might be interesting to see what if any modifications people have that are experiencing this. I have LED fog lights, a dash cam and trailer wiring harness. The dash cam has been disconnected and the problem has persisted.

 

[Hunter Mike]

I wonder if it’s your fogs. People have reported issues when replacing back-up lights with LED’s. I have yellow incandescent fogs of the stock 35W variety but have 14W LED’s on order to try.

I have dash cams that get power from the rear USB ports. It is switched with ignition so never any issues. If it’s not a dealer installed Curt hitch I would suspect the installation.

Lead acid batteries don’t like to be completely discharged below 10.5V so I surmise you hurt the reserve capacity. AGM’s are more tolerant but I’m sure that our OE battery is built to a cost. You may need to find an old-school battery tester that can throw a load at it. New battery testers use capacitance as a measure and can falsely pass marginal batteries.

 

[Wlepse]

I could put the stockers back in but since this isn't a regular thing it is hard to tell if I made a difference. But I also suspect that back up lights are more likely to cause an issue compared to fogs. With fogs the circuit is not live until they are turned on. Unlike back up lights that are engaged every time you drive, even if it is for a split second as you pass through reverse on the way to drive. Each time you do this I could see the BCM seeing the problem then monitoring that circuit to see what is going on.

 

[kevjam79]

All of the modules are linked in a controlled area network so it one module is misbehaving it can cause a communication error with all the other modules in the line. Every one of these modules can store trouble codes so it can be read by pro-level scan tools. If it’s not an emission code, it won’t illuminate the MIL. I bet you have a problem because your battery went dead and some PID didn’t like it. See if this leads you down the right rabbit hole:

State-Of-Charge And Charging Systems Diagnostics On Late-Model GM Vehicles

My ASS disabled after installing LEDs. I tried reinstalling them and it re-engaged. I subsequently reinstalled the LEDs because I prefer them and it disables the ASS which I loath. I have only noticed a significant drop in charge in the battery if it sets for more than 4 days. It is a very gradual descent in charge and then drops off fairly quick after that. It suspect it is a minor milliamperes draw on the system and it slowly chips away over days of non-use. I will try to gather some additional data on the draw over time. Thanks.

 

[Wlepse]

My ASS disabled after installing LEDs. I tried reinstalling them and it re-engaged. I subsequently reinstalled the LEDs because I prefer them and it disables the ASS which I loath. I have only noticed a significant drop in charge in the battery if it sets for more than 4 days. It is a very gradual descent in charge and then drops off fairly quick after that. It suspect it is a minor milliamperes draw on the system and it slowly chips away over days of non-use. I will try to gather some additional data on the draw over time. Thanks.

backup or fogs?

 

[kevjam79]

backup or fogs?

I had reverse, fogs and rear compartment at the time.

 

[Wlepse]

I had reverse, fogs and rear compartment at the time.

Did you ever get a DIC alert like mentioned in the link above?

 

[kevjam79]

No. As far as I am aware, that has never happened to at least the “red needle” Regal’s. I don’t believe “white needles” either.

 

[D2R]

I am here to report back that the ASS is working again on my wagon.
Turns out the battery was not sufficient enough before, hence it was not kicking in even it was about 60-ish F outside.
I left it on the vehicle charger over 24 hours to get it topped off.
The ASS kicked in even before the coolant climbed to full operating temperature. (It is 55-ish F outside today)
And I must say, it puts a smile on my face every time I get to driver her outside.

 

[Wlepse]

I am here to report back that the ASS is working again on my wagon.
Turns out the battery was not sufficient enough before, hence it was not kicking in even it was about 60-ish F outside.
I left it on the vehicle charger over 24 hours to get it topped off.
The ASS kicked in even before the coolant climbed to full operating temperature. (It is 55-ish F outside today)
And I must say, it puts a smile on my face every time I get to driver her outside.

keep us posted on if it lasts.

 

[D2R]

I will try to do that. The issue is, I can barely drive her right now with our stay-at-home order extended again and I am working from home. 😅

 

[D2R]

This needs to be a banner or something.

Nice idea.
Slapped this together at Custom Ink and is about 20 bucks a piece when ordering 10.

(Please note, this is intended to be a joke. Please don't be offended.)

 

[2007LucerneCXL]

LOL, I always thought it was funny when this first person called a dealer and said "I was in my car today, looked at my DIC and something is wrong".

 

[Wlepse]

Well my wife didn't think the shirt was as funny as I did.

 

[FavaBean]

Nice idea.
Slapped this together at Custom Ink and is about 20 bucks a piece when ordering 10.
View attachment 22293
(Please note, this is intended to be a joke. Please don't be offended.)

I just startled my wife with my outburst of laughter. But seriously, I kind of like the shirt for its inside humor.

BTW - I've copyrighted that phrase and expect residual payments for each shirt sale! 😆

 

[D2R]

I just startled my wife with my outburst of laughter. But seriously, I kind of like the shirt for its inside humor.

BTW - I've copyrighted that phrase and expect residual payments for each shirt sale! 😆

It should worn like a proof of membership during group meets. 🤣

 

[buickx]

I had this problem, the battery went dead, had it jump started.. took it to the dealer... on battery check, found it needed to be charged... completely recharged the battery.. have not had a problem since.. even after letting the car sit, without running it for three weeks, it started …..

 

[G-285849]

I am still having this problem of battery drain but only in cold weather, less than 10 degrees. If car sits for one day, it wont start. I have had 5 batteries put in under warranty. 2019 TourX Essence.