Taycan 2021 - A/C Stops After 5 Minutes - HV converter problem?

[ManuelB]

Hi everyone!

I'm troubleshooting an issue where the A/C on my 2021 Taycan RWD works normally for about 5 minutes after startup, then shuts off completely.
Diagnostic scan shows the following DTCs possibly related to the issue:

• U045600 (A/C): Thermal management control unit – signal implausible (sporadic)
• P0D6D00 (Thermal Management): Electric A/C compressor motor – voltage too low (sporadic)
• C113AF5 (High-voltage converter): Control unit defective (active/static)

It seems the HV voltage converter might be failing or sending inconsistent voltage, which could explain the compressor shutting down after a short period.

Has anyone experienced a similar issue or can confirm if a faulty HV converter alone could cause this behavior?

Appreciate any input or advice!

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[W1NGE]

Hi everyone!

I'm troubleshooting an issue where the A/C on my 2021 Taycan RWD works normally for about 5 minutes after startup, then shuts off completely.
Diagnostic scan shows the following DTCs possibly related to the issue:

• U045600 (A/C): Thermal management control unit – signal implausible (sporadic)
• P0D6D00 (Thermal Management): Electric A/C compressor motor – voltage too low (sporadic)
• C113AF5 (High-voltage converter): Control unit defective (active/static)

It seems the HV voltage converter might be failing or sending inconsistent voltage, which could explain the compressor shutting down after a short period.

Has anyone experienced a similar issue or can confirm if a faulty HV converter alone could cause this behavior?

Appreciate any input or advice!

Has you car had the heater recall work performed - if not could be related to this as there were many failures (no heating)?

 

[ct14garage]

It could be the DCDC but it's more likely to be the compressor from my experience.

you can't just look at fault codes and replace parts for the sake of it.

check the isolation of the compressor first. If it's good then take a look at actual values in DCDC

 

[stoneriver]

I had similar issues with 23 4S during a long-distance trip (4800 km) in the US W-NW. The air conditioner shut-off issue consistently occurred during DC charging stops that ranged about 320KM, and charging from 25-90%. The outside temperature typically was in the 32-36C and during the charging session I kept the air conditioner on with no issues. Immediately after the charging session, driving in normal mode, the air conditioner stopped working. Turing on/off the air conditioner, ECO mode, or the fan did not resolve the issues. The only remedy was to shut down the car usually twice and immediately turn it back on. My car is at the Porsche dealership now for diagnosis. Other than this and quirky Porsche navigation, the car was absolutely a dream to drive.

 

[truble930]

This issue was happening to me. A/C on and working fine then blowing warm air after 5 minutes. It was the A/C condenser. Lucky it was done under warranty so I don't know what the bill was.

 

[ManuelB]

Has you car had the heater recall work performed - if not could be related to this as there were many failures (no heating)?

Yes! The car heats.... the problem is to cool it down! :-D

 

[ManuelB]

It could be the DCDC but it's more likely to be the compressor from my experience.

you can't just look at fault codes and replace parts for the sake of it.

check the isolation of the compressor first. If it's good then take a look at actual values in DCDC

Yesterday I did some live analysis and confirmed the following: while the HV converter is working properly and successfully stepping down from 800V to 400V, the A/C functions as expected. However, as soon as the converter stops delivering the proper 400V output, I immediately lose the A/C and get the C113AF5 - High-voltage converter: Control unit defective (active/static) error.

This seems to confirm that the issue is directly linked to the HV converter’s failure to maintain stable voltage, rather than the compressor itself.
I'm still going to check the compressor isolation to rule it out, but the pattern is very consistent with a converter fault.

When everything is OK:

After the drop:

Thanks again for the guidance!

 

[W1NGE]

Yes! The car heats.... the problem is to cool it down! :-D

Yeah I realise that but the connection could be heater related as J1.1s have a poor record on this given the MY in scope.

No need to guess at this - that's what dealers are for...

 

[ManuelB]

I had similar issues with 23 4S during a long-distance trip (4800 km) in the US W-NW. The air conditioner shut-off issue consistently occurred during DC charging stops that ranged about 320KM, and charging from 25-90%. The outside temperature typically was in the 32-36C and during the charging session I kept the air conditioner on with no issues. Immediately after the charging session, driving in normal mode, the air conditioner stopped working. Turing on/off the air conditioner, ECO mode, or the fan did not resolve the issues. The only remedy was to shut down the car usually twice and immediately turn it back on. My car is at the Porsche dealership now for diagnosis. Other than this and quirky Porsche navigation, the car was absolutely a dream to drive.

Thanks for sharing your experience — it's exactly what’s happening with my Taycan as well.

In my case, I’ve been monitoring the high-voltage converter in real time. After the A/C shuts off, I try restarting the car. On the first restart, the HV converter attempts to provide 400V but fails — the voltage doesn't stabilize and the C113AF5 error remains active.

On the second restart, the converter usually manages to stabilize the 400V output, the error becomes passive, and the A/C starts working again as normal.

So it seems that, like in your case, a full vehicle restart (sometimes more than once) is the only temporary workaround until the converter decides to behave. Let us know what your dealership finds — very curious to hear their take on it.

 

[B61]

Has you car had the heater recall work performed - if not could be related to this as there were many failures (no heating)?

Same problem here… during DC charging (Ionity, 239kw) red error displayed… not possible to mo e car from station … after i locked car for about 30 minutes… iwas able to drive for another 100km, where i charged (Ionity) without any problems, got the same error (electrical fault….inspections necessary), but “just” in yellow, so i was able to start without waiting….

Dealer said that’s recall for heater again

Tomorrow, i’ll get my car back …with my 3rd heater.

 

[ManuelB]

Same problem here… during DC charging (Ionity, 239kw) red error displayed… not possible to mo e car from station … after i locked car for about 30 minutes… iwas able to drive for another 100km, where i charged (Ionity) without any problems, got the same error (electrical fault….inspections necessary), but “just” in yellow, so i was able to start without waiting….

Dealer said that’s recall for heater again

Tomorrow, i’ll get my car back …with my 3rd heater.

In my case, I never got any error messages—neither red nor yellow. The AC just randomly stops blowing cold air, whether I'm charging or not...

 

[ManuelB]

I had similar issues with 23 4S during a long-distance trip (4800 km) in the US W-NW. The air conditioner shut-off issue consistently occurred during DC charging stops that ranged about 320KM, and charging from 25-90%. The outside temperature typically was in the 32-36C and during the charging session I kept the air conditioner on with no issues. Immediately after the charging session, driving in normal mode, the air conditioner stopped working. Turing on/off the air conditioner, ECO mode, or the fan did not resolve the issues. The only remedy was to shut down the car usually twice and immediately turn it back on. My car is at the Porsche dealership now for diagnosis. Other than this and quirky Porsche navigation, the car was absolutely a dream to drive.

Any news from the dealer?

 

[B61]

Understood… just wanted to say, that heater failure might lead to charging problems … even if i never had any problems with AC before

 

[stoneriver]

The dealer diagnosed the issue and told me that “The AC is designed to see a key cycle after charging. It is normal.” The air conditioner worked fine for the return home. I plan to test it soon.

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