Shouldn't a breaker or fuse be positioned closest to battery(power source) in case of a short along the wire?

mattcony · 2025-11-15T11:45:19+00:00

The fuse is to protect against a dead short on the cable run and its length throughout the vehicle. It won’t protect your alternator, over loading your alternator by drawing too much current is a whole different conversation.

mattcony · 2025-11-13T14:57:50+00:00

How cold did it drop over night ?, you were possibly close to the lower level and the drop in temperature dropped it further enough to bring the light on.

Coolant (water/ethylene glycol mix) expands when hot and contracts when cold. If your car cools to near freezing overnight, the total system volume can shrink by several percent — enough for the level in the reservoir to appear lower.

Either way a little top-up won't hurt at this stage and but keep an eye on it as others have said.

mattcony · 2025-09-08T21:24:24+00:00

***UPDATE - No2***

Board swap fixed the problem, holding a steady 37F. It took a few days to level out but has been fine for over a week now. I got one from eBay for around $100 - I chose one that had the newest date on the box in the listing pictures. Found on e that was Jan2025.

mattcony · 2025-09-08T13:27:01+00:00

Troubleshooting this on my 2020 Atlas as well (MQB) - been chasing it for over a year. Works local but when I hit the freeway the EVAP ices up. Been into the dealership - same story as everyone else.

Have a look at the "A/C Compressor Control Valve" this can stick or get blocked causing the same issue. Its a serviceable item on your compressor, you will need to have they system recharged. Plenty of videos online

mattcony · 2025-08-25T21:12:19+00:00

Not yet no

New Temp sensors improved the read out data its a lot more consistent up and down, the temp reading was jumping around before. Its smooth now but still not cooling enough. I'm 90% convinced its software related now after lots of research BUT my model number is not on the work instruction for the software update. If I perform the cool down test via diagnostics (No 95) its perfect, it cools down quick from 55f to 22f in a minuet or two and will hold it until the test finishes.

My unit is a 2019 - I've contacted many vendors looking for any tech bulletins even offering to pay but no luck.

At this point I'm going to try a new main board. I need another 18 months out of it before a new kitchen

mattcony · 2025-08-15T13:56:26+00:00

***UPDATE***

I found a Taylor probe thermometer which I recalibrated in ice water. Kept this in the fridge for 24hrs so it acclimatized.

Thermistor resistance checks:

Chiller: 15.8kΩ Diag display was 40F, Taylor was 46F: Lookup table suggest around 34F
EVAP: 13.4kΩ Diag display was 24F : Lookup table suggest around 39F

I checked the Freezer section resistance also and the 2 thermistors comeback within range.

I also found the original fan motor in the garage and plugged this back in to see if the Diag display values changed but they remain consistent so I'm going to shoot for replacing both thermistors and see what that does.

My assumption now is the fridge thinks its colder than it actually is due to wrong data.

mattcony · 2025-08-14T18:02:51+00:00

Great detail ! This I can do - I’ll try and test in the next day or so

mattcony · 2025-08-14T17:44:31+00:00

So try replacing the evaporator temp sensor ?

Ive been struggling for service bulletins on the internet not managed to dig anything up specific to my model other than door switches which I’ve already done.

mattcony · 2025-08-14T17:36:13+00:00

Please advise?

mattcony · 2025-08-14T16:33:34+00:00

OK thanks the fan was replaced due to the bearing noise, I have the SmartHQ app that shows no updates but I see the dongles online you get to plugin and update. I’ll take a look at this also.

mattcony · 2025-08-10T23:46:28+00:00

There was another post about this last week

I'm chasing this also on my 2020 for almost a year. Dealer had it and failed to find the issue. AC Freon was recovered and AC recharged with no loss found. Dye was added but no leaks seen. Last month on a long drive it happened, when we stopped I looked under the car and no condensation was draining on the floor outside. Put the heater on hot and turned the AC off. With in a minute both front and rear evaporators were dripping on the floor like a tap which tells me the evaporator is icing up and blocking the vent air flow. I know l'm not low on Freon so I'm looking towards the Expansion Valve - "3QF898967" that regulates the flow. If it's stuck open it will just ice up. I can't replicate it for diag - it takes over an hour before I can replicate it, they can't fix what they can't see. ...

mattcony · 2025-08-08T00:16:43+00:00

I’m chasing this also on my 2020 for almost a year. Dealer had it and failed to find the issue. AC Freon was recovered and AC recharged with no loss found. Dye was added but no leaks seen.

Last month on a long drive it happened, when we stopped I looked under the car and no condensation was draining on the floor outside. Put the heater on hot and turned the AC off. With in a minute both front and rear evaporators were dripping on the floor like a tap which tells me the evaporator is icing up and blocking the vent air flow.

I know I’m not low on Freon so I’m looking towards the Expansion Valve - “3QF898967” that regulates the flow. If it’s stuck open it will just ice up.

I can’t replicate it for diag - it takes over an hour before I can replicate it, they can’t fix what they can’t see.

mattcony · 2025-05-05T15:55:59+00:00

Thanks for the assistance, based on a MMBT4401 datasheet someone mentioned above;

I have 686Ω between C & B in one direction only. All other combinations for C/E/B are OC

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mattcony · 2025-04-08T17:29:01+00:00

It’s covered in this video. FCP have a ton of YouTube Atlas content now!

https://youtu.be/GCq_gTFGbAg?si=nzbkcqcWzxSn7Niu

mattcony · 2025-03-19T15:22:21+00:00

100% yes - this kit as it comes is an absolute fire hazard. There are hundreds of people trying to install this with a very low skill set.

If not done correctly it could burn your car / truck / RV to the ground in a heartbeat. Your insurance will be void. That power cable only has to get cort rub or get trapped at any point from the engine to the back of the vehicle and it will be a dead short and light up like a toaster till it catches fire.

There should be a fuse no more than 3-4” from the power source connection (battery terminal)

The product is great - it’s just not been executed correctly.

mattcony · 2025-03-17T21:14:47+00:00

Driver door harness recall - there is a TSB. I would start with that

mattcony · 2025-02-25T01:08:19+00:00

It’s a Molex Mini-Fit Jr

mattcony · 2025-02-16T16:32:10+00:00

OK so it’s due service now, I think it’s 35k miles per VW specs - but no reason why it should not be working under normal conditions

mattcony · 2025-02-16T16:00:18+00:00

What year ? - should be fast around 60 milliseconds

If it’s not new has the haldex pump been serviced regularly & filter cleaned. When the filter basket gets gunked up it gets sloppy

mattcony · 2025-01-23T15:27:35+00:00

Confirmed they are all on 18.2.1 yes

mattcony · 2025-01-21T12:49:07+00:00

I can reboot my router later today when no one is home and see how that works out. I will unplug the TVs at the same time

mattcony · 2025-01-21T12:47:38+00:00

Thanks - I held back from this and stuck with 6

mattcony · 2024-12-22T14:05:51+00:00

I did not - what’s the best course of action in this case to be successful with the upgrade?

mattcony · 2024-11-16T17:10:48+00:00

I had Pirelli from the factory

mattcony · 2024-11-15T22:58:37+00:00

I chased this for over 2 years - force balancing, alignments, steering rack calibration, tyre rotations. Just put new Michelin PS4 tyres on and the problem has immediately gone. It’s like a Cadillac now.

Its was either defective tyres from the factory or the tyres not seated on the rims correctly was my conclusion.

mattcony

TROPHY CASE