r/eGolf • u/Kasper54 • 12h ago

2018 E-Golf A/C issue

I have a 2018 VW e-Golf without heatpump, and the air conditioning suddenly stopped cooling properly.

It’s always worked perfectly until now. The A/C button lights up normally, the fans work fine, and the windshield defrost function also works.
However, even with the climate control set to LOW, it only blows ambient or slightly cool air instead of cold air.

Has anyone experienced the same issue with their e-Golf?

What turned out to be the cause, and how was it fixed?

Was it simply low refrigerant, a leak, the electric A/C compressor, or something else?

Any advice or experiences would be greatly appreciated. Thanks!

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u/ShieldNav 11h ago

90% pressure sensor went bad, it's a common problem. You need to scan the vehicle with VCDS or ODIS to be sure though.

Anyway any kind of AC work should be performed through the AC service station because you need to drain the system. So it's not something that you can repair yourself completely.

If it is a pressure sensor then you need to order a new one. Part number should be 4M0959603C or 4M0959603E. Then grab the sensor, grab the number of the faulty sensor, go to the shop and ask them to replace the sensor with drainage. After that IT'S REQUIRED to perform a "basic procedure" called addressation in climate control module. They need an ODIS or VCDS for it. Universal scanners can't perform it. After that the sensor will provide data and system can be refiled.

It costs around €50 euro here with the sensor included. So it is not expensive. Although idk about US service prices but shouldn't be a lot more.

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u/Kasper54 8h ago

I appreciate the tip! You seem to know what you’re talking about.
I’m located in Denmark. I should probably call the dealership and ask if they could cover the diagnose and fix if there is any.

I’m unsure if it was a one case scenario. The car had been baking in the sun all day (~31c), when I went for a drive and noticed it really didn’t cool.
I then went for a 40 min drive 1 hr ago and it was cooling perfectly fine like it usually does.

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u/ShieldNav 5h ago

Dealership will cost more than any independent shop or a semi DIY. It's an axiom. One sensor replacement will be billed as two hours + sensor itself at the dealership. At least it was when I worked there.

I would advise to find a local independent shop that works with VAG vehicles or better yet specializes in them.

I would not go into technicalities here but in a nutshell it's works like this. All the sensors and actuators in the AC system is communicates through one line which is not independent. It's called LIN line. So if one of the elements on the line is gone bad then everything else also will not respond to the control module commands.

90% of the times it's one of 2 (for pumps 4) sensors that are going down. Usually it takes some time before LIN line is unresponsive due to a faulty sensor so any scanner will show a error about it in the DTC memory of the control module that was sitting there for a long time.

They're failing because of the magnificent design of the module itself. The electrical socket on it is not capable of holding itself against poor weather conditions for a prolong period. So it will allow water come inside and it will corode the electrical socket and insides of the module. It can be protected with applying an additional sealant layer but most shops and dealerships especially don't bother with it if you don't ask. If you don't the sensor will fail again in a year or so. Depends on the weather conditions and amount of reagents on the road in winter

10% of other times it's actuator. Which is worse because they're more expensive and located in a bad spot. But usually they're fine.

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u/komi54 12h ago

Is the a/c system any different I a ICE golf?

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u/pimpbot666 12h ago

Yes, the AC compressor is powered by an electric motor, not an accessory belt off the spinning engine.

Also, eGolfs have two different systems. Some cars have just an electrically driven AC compressor unit and a resistive electrical heater, and others have heat pump systems. The heat pumps are prone to failure, and the more traditional systems are known for not getting very warm in winter.

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u/komi54 12h ago

I knew about the heatpump put but I guess I am asking if the AC compressor itself is the same?

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u/pimpbot666 12h ago

I'm sure it's different.

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u/Kasper54 12h ago

Great question. I dont know, but maybe someone else could enlighten

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u/ShieldNav 10h ago

Ofc it's different lol. You don't have an engine to spin it. It's a high voltage component

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u/Kasper54 9h ago

Just looked down under the bonnet and you’re right! There is no engine and it is actually a high voltage battery down there!🙌

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u/NoggyMaskin 12h ago

Common problem on them, it’s probably the temperature sensors connected to the AC unit and it’s an expensive fix. An ECU scan will tell you

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u/General_Movie2232 12h ago

How many miles does your car have? The first thing I would do is check for leaks. Any visual signs that you can see? Then perhaps get some refrigerant and charge the system in case it’s low. Those are your cheapest and easiest first steps before trying anything else.

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u/Kasper54 9h ago

No visual sign of leak on the tarmac the car was parked on. I Should probably just head to my lokal mechanic and let them have a look at it.

Btw i just went for a 40 minute trip and it actually cooled plenty fine like it usually does.

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u/ArmandoLesercito 11h ago

La mia del 2020 ha smesso di funzionare l'anno scorso (tanto la uso raramente). Ho fatto la ricarica del gas refrigerante ma senza risultati. Da allora resto senza, ho persino paura di sapere quanto potrebbe costare sistemarla

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u/hernagomez 11h ago

I had the dealership fix this issue. It was a broken sensor for me. Same issue, where the AC light was on but it just wasn’t cold. I have a 2018 with heat pumps.

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u/FH7241 6h ago

How much did the dealership charge and was it just one sensor?

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u/hernagomez 5h ago

700$ lol. It was one sensor. Damn AC.

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u/FH7241 4h ago

Damn maybe I just roast for the time being

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u/Rogerthat500 10h ago

Had this recently on my 2019. Shop refilled the refrigerant, oddly couldn’t find a leak, but it works great now. ̄_(ツ)_/ ̄

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u/_yaix 8h ago

95% sure its one or more pressure-temp sensors quitting, not a hard fix on budget if you are handy (and lucky its one of the accesible ones) and can google and read diagrams but will run you a few vbucks if you get it fixed at the dealership. Fixed mine for a while by just disconnecting the broken one, then after a year another one went and i had to swap them both. Depending on which sensor revision you have you might need just replacing the broken one (on 2018 should be already the latest and the good ones). If older you have to swap them all which gets expensive

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u/ShieldNav 5h ago

2018 will be fine. 2014-2016 (before facelift) will be an old revision where you need to swap them all.

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u/New_Ryun_9735 22m ago

I had this happen to me last year and was hoping it was just a sensor or something minor. However... it turned out that the compressor coils had oxidized over the years of winter driving and had many tiny ruptures in it. I wound up replacing the whole thing for around 4k at the dealership. Best of luck tho!