Temperature sensor for climate control is faulty.

Passat Variant TDI 90PS 12/95

My Climatronic blinks for about 15 seconds every time I start the car, which, as far as I know, indicates an error. After my last visit to the workshop, the gentlemen told me that it was probably the temperature sensor. Cost: 113 Euro.
I removed the interior sensor (on the right side of the steering wheel) today and saw that there were just two cables ending there. (It's a used car). This seems not quite right at first glance. Does anyone know what the sensor looks like exactly? And what kind of electronic component is it? Ideally, I would like to buy the sensor at the electronics store, and not the entire component including it. Fans at VW.

Then, here's another question. I haven't had the car for very long, and I'm not sure exactly what its maximum speed should be. A top speed of 180 km/h is the limit. If you press the accelerator all the way to the floor, it takes a while. Sometimes, the system isn't quite clear to me, and it loses power at 160-180 km/h. It feels like a rev limiter. So, wie schnell müsste er laufen, und was könnten diese Aussetzer sein?

Hello,

The climate control system has more than one temperature sensor to determine which temperature is currently set. You could try the following:
Search online for a diagnostic menu for VW/Audi (different depending on the year and manufacturer) for the climate control system. Using specific key combinations, you can read out the measurement channels. Then, check all temperature measurement channels for plausibility.
Based on my intuition, I would first check the temperature sensor for the outside temperature, which is located on my A3, for example, on the left front in the front bumper. It's possible that a fox has chewed through the cable or that the connector doesn't have a good connection. Whether this actually causes an error entry and/or total malfunction, I cannot tell you.
Otherwise, you'll have to bite the bullet and go back to the workshop, connect the diagnostic device to the climate control system.

Hello, Rainer

Hello Rainer,

'Going to the garage' sounds quite nice. Basically, I've been getting my cars repaired in the garage for a while now. Now, I recently had to replace my boost control valve.
When I looked at the invoice, I almost fell over: Fault code reading 10 Euro; Reading of measurement data 25 Euro, Checking of boost pressure regulation 28 Euro; Replacement of boost pressure regulation valve 23 Euro, plus of course the material costs.
Subsequently, I then searched the internet for other options. For a simple reading of the error code and the reading of the measurement block, I paid around 35 euros. I should actually be able to do this myself. I'm not quite sure how the check of the boost pressure control works. All in all, I definitely plan to consider purchasing software with a connection cable, such as VAG-COM. I could also test the air conditioner myself.

Do you have experience with the diagnostic tools? Can these tools be used to accurately check the entire turbo range and the fuel injection, or do you still have to perform mechanical tests with special tools afterward? Basically, I am already able to understand and repair a car. I haven't owned a TDI yet, but I used to do all the repairs myself. How can I save money like this?

Regarding the temperature sensor: Regardless of the number of sensors, the next one was simply the one to the left of the radio. And there, I just saw that there were only two cables ending there. And that makes me wonder if such a sensor would look like that, or if there would still need to be an electronic component there. Maybe someone has actually built one and can describe it visually.

Best regards, Matthes

Hello,

with VAG-Com, you can do everything that the 1551 can also.
However, it is recommended to have documentation for your engine, then you will not have to guess whether the displayed temperature reading is the engine temperature, the fuel pump temperature, or the intake air temperature.
A diagnostic tool cannot replace human reasoning, but it can significantly save time and speed up troubleshooting.
If I read that you charged me 35 euros for reading error codes and looking at some measurement values, it really makes me angry...
The maximum speed is listed in your vehicle registration document. Add 10 km/h to the speedometer's accuracy (or have the speedometer checked by the ADAC, then you'll know the deviations), and you'll have a good estimate of what's allowed.

Hello, Rainer