Not ok to start, trying to understand errors. GTW_w018, DI_u014, GTW_w406

[T Alvous]

Hello everyone! I have looked around a bit but haven't been able to find a similar issue.


Model S P85+ 2014
Main battery was replaced at the start of this year after a total failure

Around the end of September, I began to get GTW_w018 (Electrical system power reduced) errors that would show up, cut my AC, and then disappear a second later a few times every other drive or so. Over the last month, I have noticed that they only show up when it is above ~70F outside.
That was relatively harmless, so not as much thought was given to it as it probably should have.

So, his morning I went out to run an errand, and the car was powered off, upon turning it on it flashed a bunch of alerts at me (GTW_w018, DI_u014 Voltage supply too low, and GTW_w406 12V Not Supported) that said that there was low power so systems were shutting down, and the car was not ok to drive. Yesterday there was a very heavy rainstorm that I had to do a lot of driving in, I assume this may have caused this more serious issue.

Does anyone have thoughts on what it may be? I think I will need to make a service appointment, but I want to see if it happens to be something fixable by me, and if not then go in with information to hopefully cut down on troubleshooting time.


Attached are photos of the service alert pages. The first was taken on October 1st showing intermittent GTW_w018 errors, and the 2nd/3rd were taken this morning, the blue lines on number 2 show the breaks in time.

 

[DerbyDave]

Likely the 12V battery needs replacing.

 

[T Alvous]

I had a feeling that was the case.
Would you guess that is the only issue at play here? Or at least the only that can be gleaned from this info?
It was replaced with the high voltage battery at the start of the year, and 9 months isn't a long service life.

But thank you!

 

[DerbyDave]

It may not be the 12V, but that is where I would start. Maybe take it out and to auto parts store with free testing to see if it is showing any issues. The logs show lots of low voltage and 12 volt errors, and if it is not working properly, maybe even if the ground is bad, it will throw a bunch of other errors.

 

[T Alvous]

Gotcha, I'll go do some testing on that and report back with the findings in a few days.

 

[T Alvous]

Updates!

I went out this morning and the car was working again. The screens turned on and would shift into drive, however, there is now a regen restriction to about 20kw, and the battery has dropped nearly 8 percent just sitting there since two days ago. I took it around the block to a supercharger and it would only accept 20kw so something has been triggered in the software, but I didn't see any error messages that would explain the new charge restriction.
I also got a whole bunch of 12V not supported errors when I pulled out of the parking garage.

Does anyone know what these two errors mean?
EPAS_d076_KFC_DAS_TIMO
THC_d0021_RCCMActuator

I have a mobile service scheduled for the 6th to replace the 12V, unfortunately the 2014's have a really stupid battery placement so I can't check it myself. I tried using the connectors behind the nose cone on the front bumper to check the voltage but every way I tried it, including doing exactly what was in the tutorial, caused sparks to fly and nothing to show up on my reader so I decided not to screw with it.

Any reasons I should leave it alone and find other transport? I think I am going to drive it like a baby till the 6th, and hope it doesn't damage anything else.

If the battery doesn't fix everything then I guess the front left louvre is to blame? Maybe it's stuck in some way that it pulls a bunch of power or something who knows.

 

[DerbyDave]

Tesla has recently provided information on all those errors and what they mean in the Service menu. There is now a down arrow on the right side of each error. Click it and almost all information you want will be there, including if it needs service or not.

 

[T Alvous]

That was the first place I checked, it was not as helpful as I was hoping for.
Though after driving about two miles to grab groceries the regen/charge limit seems to have been removed which is good. But after getting back and reopening the menu I had like 30 12v not supported warnings in a row.

Also, I do apologize if I am missing any proper form etiquette, thanks for your help.

 

[DerbyDave]

EPAS_d076_KFC_DAS_TIMO
There is a missing message, and the DAS_steeringTorqueControl (0x488) has timed out.
On vehicles without Drivers Assistance System (DAS) hardware, this alert can be ignored.
----This error could be transient and not important yet.

Your left front Cooling louver under the bumper may not be opening, or having a problem. This also may be relating to the service required for climate control, since this could cause cooling issues for both the interior and battery connected cooling system.

 

[T Alvous]

Right, I was planning on taking a look at it tomorrow and give it a poke or two. I'll do some research on how easy it is to access, from what I have seen it will likely be a bit more complex than what I can really do. So if it doesn't go away with the new battery I likely have a service appointment in my future.