Climatronic Problems: Codes 4F8 & 4B6 Explained

Hello,

My Climatronic system (in a Golf IV TDI, 7.5 years old, with 185,000 km) is no longer working as it should.
The heating system only provides properly warm air when the Climatronic is set to "HI," which means the compressor is turned off. Otherwise, it cools well.
The error codes in the fault memory are 4F8 (actuator motor for central valve 0x25) and 4B6 (dwell time signal 0x25). Can anyone tell me how to interpret these? What does the dwell time signal 0x25 mean?
An ADAC technician read the error code 1272. Will this help me?

I cleared the error memory and started an actuator test. This was completed without any errors. While it seemed to be working better, the Climatronic still wasn't functioning properly. The errors reappeared after a while (during a multi-hour drive), initially code 4F8, and now code 4B6 has also returned.

Regards,
Michael

It seems like a different speedometer was installed later.

Julian wrote:

Was if a different speedometer was installed later?

No, not that I'm aware of – and I've had the car for 125,000 kilometers.

I've been checking some values using the Climatronic's internal on-board diagnostics. I noticed that the temperature reading on channel 1 is constantly increasing, even though the interior of the car is definitely getting colder. (Channel 1 is supposed to represent the interior temperature; the other channels seem plausible at first glance).

Regards,
Michael

aMiGo1998 wrote:

... that the temperature on channel 1 is constantly increasing, even though it is definitely much colder inside...

Okay, so it seems that's the explanation: The interior temperature is not being measured correctly. I would thoroughly examine the sensors and cables.

If the central valve is responsible for temperature control, then the error message "Central valve actuator" seems plausible. The background is that it (falsely) detects that the interior is heating up and tries to compensate by adjusting the temperature valve. Since the interior continues to get "warmer" (or is falsely detected as such), the climate control system thinks that the actuator for the temperature valve is defective.

There's only one thing left to check: whether my theory was correct, specifically whether the central valve and the temperature valve are the same thing. (I don't have my documents handy right now.)

Regards,
Sure.

Here is the translation of the text from German to English:

"Guste" means "gust" in English. It can also be used as a verb, meaning "to gust."

There's only one thing left to check: whether my theory was correct, specifically whether the central valve and the temperature valve are the same thing. (I don't have my documents handy right now.)


No, because the operating time of the air conditioner is displayed in that channel, so it's clear that it will be running.

The flaps are the same. If the interior sensor is defective, it will first be indicated, and secondly, its readings will be compared with the temperatures from the water tank and bumper. The sun's position must also be taken into account accordingly.

If the temperature flap motor is already showing a defect, then it should be removed/replaced. What is the purpose of the error memory in that case?