12V Battery & DC/DC Converter issues

[VegarHenriksen]

I have a 2015 S which is having some issues keeping the 12V happy. Sometimes when I get in my car after it has been parked it refuses to drive, saying voltage supply is too low. Sometimes I need to lock and unlock and other times I need to disconnect + from the 12v for a little bit in order to drive.

When parked, especially overnight the car will die and wakeup multiple times throwing these errors
GTW_w017
GTW_w018
GTW_w157

When car is awake it regularly throws GTW_w405 12v not supported.
If the voltage supply error is present refusing to go into drive it will throw DI_u014 unable to drive

When it refuses to drive the 12v will be at 13.2-13.4V
Other times it will be at 14.2-14.4v and be perfectly happy
It can jump between these just by going from "car off" to PRND

DC/DC converter is showing an output of 14.1V when the 12v battery is at 13.4V.
If the 12v is at 14.4V it shows an output of 14.6+v

The 12V battery is around 3 months old and I have swapped in a brand new one just to test, same behavior.
I have the Gen 2 DC/DC and have checked for corrosion in lower A pillar connectors as well as damaged wires around the converter connectors without any luck.
If I remove the voltage sensor from the 12V battery it jumps to 65+ volts so it seems like the sensor is okay

Sometimes if the battery drops down to 13.xV I can see it slowly climb back up to 14+V

Does anyone have any idea?

 

[Gtech]

If you already checked power/ground connections from DC/DC and car is not throwing HV errors Maybe DC/DC is getting bad? Normally I would not start firing the parts cannon but maybe you can get a used DCDC for cheap and try swapping it?

 

[VegarHenriksen]

If you already checked power/ground connections from DC/DC and car is not throwing HV errors Maybe DC/DC is getting bad? Normally I would not start firing the parts cannon but maybe you can get a used DCDC for cheap and try swapping it?

Toolbox shows everything as okay with DC/DC converter, outputting 13.9V when 12V battery is at 13.4V. 14.5V when 12v battery is at 14.1V
Looking at another S it seems to have the same voltage ranges

 

[cmaster]

I'm wondering if it's electrical noise carrying over from the DC/DC converter that causes it to become intermittent. Or, an unsealed PTC heater core, moisture could probably got into it. It might not be that, but, could be since Tesla changed the design on the seal from the non-refreshed to the refreshed model.

 

[VegarHenriksen]

Sitting in drive at 13.4V W405 comes up as often as every 20 seconds

 

[VegarHenriksen]

Measured X950 in A-Pillar and V there is identical to what the 12v battery measures. What a stupid fault..

 

[VegarHenriksen]

Uhmm