Lost AUTO Temp Controls after new battery

[stretch78681]

For the second time in a month my battery died. I decided to replace it. Using normal practices. Remove ground, then lead. Upon replacing the battery in same manner, the vehicle started and all was good until we got on the road. With the 8” A/V control in my 2018 Bighorn 4dr, I seem to have lost temperature control. I have “HOT” or “LO”, and fan controls. LO, with MAX A/C I get air conditioning. Otherwise I get heat. I did hold my finger on the circle around HI, the temperature numbers displayed, I set the control to 72, when I released my finger, the display went to LO.
I have held buttons down, counted to 10, checked fuses. Nothing changes.

 

[Sherman Bird]

According to my service info, You need a scanner to reset any codes.

 

[clay282]

.

 

[SitKneelBend]

For the second time in a month my battery died. I decided to replace it. Using normal practices. Remove ground, then lead. Upon replacing the battery in same manner, the vehicle started and all was good until we got on the road. With the 8” A/V control in my 2018 Bighorn 4dr, I seem to have lost temperature control. I have “HOT” or “LO”, and fan controls. LO, with MAX A/C I get air conditioning. Otherwise I get heat. I did hold my finger on the circle around HI, the temperature numbers displayed, I set the control to 72, when I released my finger, the display went to LO.
I have held buttons down, counted to 10, checked fuses. Nothing changes.

As previously stated, if the radio looses power it will take several hours/power cycles for the features to read correctly after the BCM is read.

 

[tron67j]

Already said it all above, do a few start, run 20 minutes, shut off cycles. Repeat a few times over 24 hours. All should be back.

 

[stretch78681]

According to my service info, You need a scanner to reset any codes.

No codes…

 

[stretch78681]

After a power loss... the canbus's can take up to 24 hours to find everything again and activate it. Not unusual. Give it a day.

Three days, 450 miles.

 

[clay282]

.

 

[Sherman Bird]

Time to sell it for scrap. LOL!

I'd try one last thing and PULL the battery terminals. Let it sit overnight to fully drain off any residual power. Then connect the battery and see if it finds everything and initializes it. Short of that... a trip to the mechanic. Auto climate control is electronics and not as easy to trouble shoot.

You are proposing a deep reset. Both terminals MUST be removed from the battery and a 100 ohm resistor put between them as you connect them. The MAXIMUM time for this connection is about 18 minutes. Either it works or it doesn't.

 

[Wild one]

Pull the negative cable / step on the brakes for a minute or 2 and turn on the headlights at the same time,then reconnect the negative cable and don't touch the truck again for at least a couple hours,do not cycle the key during that time,and see what happens

 

[stretch78681]

You are proposing a deep reset. Both terminals MUST be removed from the battery and a 100 ohm resistor put between them as you connect them. The MAXIMUM time for this connection is about 18 minutes. Either it works or it doesn't.

That was what happened when I replaced the battery.

 

[stretch78681]

Well we drove from Austin to Houston Monday, after the installation of the new battery. Today, Wednesday at the third start up today, about 15:00, the ATC Display was back to normal showing temperature in degrees not Hot or Lo. Thanks guys.

 

[Dusty]

Situations like this are usually avoided by disconnecting the two-wire IBS connector that's part of a sensor mounted to the negative terminal of the battery. BEFORE disconnecting the positive or negative battery cables.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 124583 miles.