2019 Ram 1500 Big Horn - Chaos After Battery Replacement

[jmhecker]

I went to start my 2019 Ram 1500 Bighorn yesterday morning and nothin. Just the dreaded staccato clickety-clack of the starter trying to engage. I checked the main 12v battery under the hood, and it reported just shy of 10v. Threw it on the charger for a while, and couldn't get it to get any higher. So, I swapped out the battery. Something that I have done many times in my life...on vehicles that were less 'computer centric' than today's vehicles are.

Anyway, new battery is in, and it started right up. Yay! ...or so I thought. Almost immediately there was the CEL brightly lit. Followed up by the Battery light.

So, I threw my OBD2 scanner on, and saw these codes: P0AA1 (x2), P1618 (x2), U0412 (x2), P0AC0, and P1DF3.


This is what the Battery pane of Vehicle Information looks like:




I assume that the Battery Voltage pane is showing the voltage for the 12v battery under the hood, and not the eTorque battery...right?

I cleared the codes to see if they would come back, and they did, almost immediately. I tried to pull the 12v battery and let it sit for a while to see if that would help 'reset' things, and it didn't,

What else should I be looking into? Or is this now a "take it to the shop" moment?

Side note: I just had it at the dealership a few weeks ago where they rebuilt the top half of the engine and I think they also updated the firmware on the ECU. They did mention at that time that the battery should be replaced, but I was not about to pay their outrageous price for it. (the other work they performed was all covered under warranty).

 

[kapinallinen2]

Measure the 12 volt battery voltage with a multi-meter while the truck is running.
If it truly is 12 volts then the DC to DC charging system from the 48 volt side might have failed.

 

[jmhecker]

I just checked that at your recommendation, and while running the battery is reading 11.6v and the Battery Voltage reading on the dash was also reading 11.6v...what does that indicate?

 

[jmhecker]

On my way to work this morning (a 5 mile drive) the truck decided that it did not want to continue driving. I lost everything electric (radio, steering, lights, hazards, instrument cluster, etc.). Luckily I was not on the interstate because that could have been disastrous!

I had it towed to the dealership and they called me last night saying that they just had to do a software update and it should be good to go now, but they are going to have one of their porters take it for a test drive around town today to see "if my concerns about the vehicle are resolved". ...Uhh..."My concerns about the vehicle"? You mean the fact that it doesn't turn on or drive? Yes, test that, please!

What I can't figure out is this: I had the truck in just about a month ago for a lot of work to get done before my extended warranty ran out...wouldn't they have flashed everything then when they were fixing all of the other electronic issues it was having? The only new NHTSA Recall that is out for the truck that is not complete is the one from September 4th of this year for the ESC. (FCA Link) I do not know if that is related to the issue I am having or not, but it will be interesting to see the results.

 

[jmhecker]

Here are the notes from the Dealership Service Team:

Verified concern that the vehicle has a battery light on and a warning message. I started the vehicle, but it died when I tried to drive it, and it dropped the voltage right away. I then pushed the vehicle inside, used a battery charger, and was able to power on the battery. I found active codes:

• BPCM P1618-00 Sensor Reference Voltage 1 Erratic
• BPCM P0AA1-00 Hybrid/EV Battery Positive Contactor "A" Stuck Closed

I started by performing a flash for these codes, updating from the current part number 04610376AK to the targeted part number 04610376AU. After performing the flash, I had a pending code P0AC0-00 Hybrid Battery Pack Current Sensor 1 Circuit Performance, so I followed the diagnostic chart, which led me to check the 48V connection at the MGU. I verified that the connection was tight, then started the vehicle, and the codes went away. The vehicle is now running fine and charging. I charged the battery and plan to let the vehicle sit overnight and drive it in the morning.

I have driven it a couple of times since it has been in the shop, and it *seems* to be back to normal. Well, 'normal' meaning that I still don't have audio in the drivers side door and the driver side dash tweeter. (you can read more about that adventure here)