Service Required - GTW-W021

[Ulfilias]

Hi There,

Posted bits about this on Facebook (Telsas owners club UK), but not sure about the searchability there and thought I should document for others!

This Message popped up whilst driving Saturday. Service mode gives GTW_W021_thcMia

A facebook user posted "Thermal Controller Missing in Action" - Which appears about right.

The car drives FINE, which is different from any net search. Everything appears pretty normal, plenty of beans etc. However the climate control doesn't push out air. Low/High, the controls work on screen but nada, zip, nothing!

I ran a multi-meter across the frunk fuses (Pulled the fire loop first) and swapped the relays that matched between slots (hoping to loose rear defrost) but everything was the same

Contacted Tesla and 4 days later they're back with an estimate £330, though interestingly that mentions £25 for changing a relay (1011602-00-A 40v, 12volt) and Low voltage Circuitry Integrity check at £165 and a half hour on the climate control - though I believe this is car restriction because of keeping stuff for the Thermal Controller!

Tesla Service Appointment booked for Tuesday. Will see what happens

Lee

 

[houstonian]

Appears this user had a similar issue: Error GTW-w021

 

[Ulfilias]

Saw that one on a web search a few days back, but sods law, not on a search directly on this site.

Same error code, but that case stopped the car driving!

 

[NewbyMaybe]

There's a ground post on the frame under the frunk that can look okay but actually be corroded.

 

[Ulfilias]

So....A day at Tesla!

Initially I thought we were off to a good start. There was a Fuse - F114 that i'd missed when checking. Seems if using a multi-meter across them you need to pull the 12v battery and then the Fire loop to kill everything. I normally pull fuses, and check each one, but was in a rush at the time!
Anyway an hour £50 and a bit of knowledge and away i went!!!

However about a mile or so and on the dual carriage way, the error returned, I swung round a roundabout and back to Tesla. The tech was dealing with someone else and I waited a couple of hours. He then went through a few things, theorised bits, tried things and NOPE

I left at 6ish with the bumper harness disconnected....after picking up some food, hit the dual carriageway and FAULT - Curiously the climate whilst putting out air, didn't get cold, even set at 16 degrees C -

I'll also mention that there seems to be a high pitch hum from the frunk area and in leaving the car static for a few days it lost more battery than expected (expected a few miles normally, got 30+ loss). Plugging the granny lead in at home over night charges the car from the 30-40m daily and it finishes in the early hours, but I noticed that the car started charging again later on in the morning

I've included the updates from FB i made during the day, with the tech trying to trouble shoot, just in case extra info - I know i'm verbose, but things like this are good if I have to come back later etc
---
In at Tesla Northampton - Fuse F114
Interestingly I'd run a multimeter across the top of these (fire loop pulled) but you also need to pull the 12v battery first... I should have pulled all the suspect ones anyway, but damn!
However got a mile or so down the road after before the error returned and I bet the fuse blew

Swung back round and waited an extra hour and a half, but let's see what happens next!

Now checking wiring as seems it can be an issue..... Or the BMS heater. Curiously NOT a battery/drive train warranty part

Though also seems may not be silly expensive, despite having to drop the battery pack (30 mins on an S

) - however that'll be a rebook item!


No definitive answer today

Seems the bumper harness can be an issue, so unplugged, new fuse, will see if blows in use!
Going to lack parking sensors just like the modern cars

 

[Ulfilias]

Just popped a F114 fuse in. The high pitched whine appeared to stop.
I got in, powered up and dropped climate to low. Sat for a good few minutes with warm air blowing (warm day, but), which says there's something cooling related.

Pet theory is that there is something in the heating / cooling with a stuck electrically operated valve, the torque of which when operated draws too much current and pops the fuse.

Car at low speeds, I believe is fine, but when I hit a dual carriage way and give it some beans the TMC turns on the cooling and pops the fuse

 

[Ulfilias]

The Car popped the fuse on the way home, was on a straight back road in cruise at 60. I tried to baby the car driving home to see if being gentle helped. NOPE

I then parked the car up on Thursday evening. Swapped the fuse as there may be some run on / parasitic drain with it popped (high pitch whine from bonnet) - Picked the car up late Monday night and drove home. Was 12 degrees C and i did 20 miles home without it popping, was a very gentle cruise as i was knackered from a 20h coach trip and camping festival!

Didn't blow on the way in to work this morning either which was unexpected.

Tempted to find where the tech disconnected the bumper sensors, he thought it may be the loom. Think that theory is false after two pops and i'd like my outside temp sensor and parking bits back.

 

[Ulfilias]

Finally sorted!

Took a while as service had people off and illnesses and tracking the fault - Got given a 2020 model 3 LRD as a loaner though which was fun!

They ended up swapping a front bumper harness - 1004420-04-T

£125 for the harness, £99 to fit, £250 in diagnostics - All plus vat, so about £580 - I also got a wiper motor to DIY which made the bill higher and way more complex than it needed to be!

Can't say i was convinced on wiring, but aircon works, will find out on a warm day when driven hard etc

 

[Nissanman]

Finally sorted!

Took a while as service had people off and illnesses and tracking the fault - Got given a 2020 model 3 LRD as a loaner though which was fun!

They ended up swapping a front bumper harness - 1004420-04-T

£125 for the harness, £99 to fit, £250 in diagnostics - All plus vat, so about £580 - I also got a wiper motor to DIY which made the bill higher and way more complex than it needed to be!

Can't say i was convinced on wiring, but aircon works, will find out on a warm day when driven hard etc

Glad it got solved, thanks for posting the resolution! What year is your "S?"

I bought an older (2014) S85 a few months ago; got a screaming deal, but I'm a bit worried about these kinds of things popping up. At least you weren't stranded by the fault!

 

[Ulfilias]

Mine is a 2017 100D

It's an awesome car, but all cars tend to need a bit of TLC and problem solving to keep them going.

I've just had the battery pyro fuse needs changing, so have one on order
Got a new wiper motor too as the bushes die and an arm scrapes on the underside of the bonnet. Also want to swap the back-up camera as it has a cracked lens and washing knocks it out for a day or two, plus better image on the new one. Just did the fan jet washer upgrade.

Most of it is minor niggles, so better for DIY, but I'd have never solved THIS issue on my own!

 

[livesmith]

Mine is a 2017 100D

It's an awesome car, but all cars tend to need a bit of TLC and problem solving to keep them going.

I've just had the battery pyro fuse needs changing, so have one on order
Got a new wiper motor too as the bushes die and an arm scrapes on the underside of the bonnet. Also want to swap the back-up camera as it has a cracked lens and washing knocks it out for a day or two, plus better image on the new one. Just did the fan jet washer upgrade.

Most of it is minor niggles, so better for DIY, but I'd have never solved THIS issue on my own!

Hmm, I noticed on my 15' 85D that there's an odd wear spot on the hood in front of the driver that my mechanic said looks like it must have been the wiper from pervious owner. They seem to work now, but there is a bit of slight clunk when the wipers change direction. Is this just a bushing that can be replaced?

What is the fan jet washer upgrade?

 

[NewbyMaybe]

Clunk is from worn out parts, probably the fitting at the base of the wiper arm. If you put the wipers into maintenance position you can wiggle each one to determine if it's one or both.

 

[Ulfilias]

Hmm, I noticed on my 15' 85D that there's an odd wear spot on the hood in front of the driver that my mechanic said looks like it must have been the wiper from pervious owner. They seem to work now, but there is a bit of slight clunk when the wipers change direction. Is this just a bushing that can be replaced?

What is the fan jet washer upgrade?

I've also got a similar wiper wear issue. I've got a new motor from Tesla to fit at some point. I put a bit of paint protection film and tweaked the bonnet until i get properly sorted. I'm guessing you COULD replace bushings, but Tesla doesn't sell the bits, so it'd be a DIY source.

There's a video here on the washers - I have the cold weather pack so i ground out the heater on my old twin jets and epoxied them into the new ones. Took me an hourish to pop the old ones out, modify and fit the new ones. Maybe 10 min job without mods. About a tenner for a pair from Tesla service centre and now one of the jets doesn't always hit the wiper arm and they don't require adjustment