No heat. 2015. Pressure sensor error.

[Philipnjf]

Hi all.
Long story, bought my egolf knowing that heating was not working. It was a small no brand dealer, they had changed the 3 pressure sensors that was making errors. But they had not given them linbus adresses.
I took the car to a guy I known that has an original vcds, and knowns how to use it.
He could give 2 sensors an adress, but not sensor no 5.
Now has anyone heard of this before?
I can see that the hvac has the old 0107 software. And could/should be updated to 0203.
Could this maybe solve the problem?
Any other suggestions?
Best Regards. Philip

 

[Philipnjf]

So tried to read the codes with vcds. Maybe it makes to somebody here? The pressure sensors has been changed. But I can not use the command to give adresses to slave components. Everything looks like a bus problem. I will have the software of the heatpump updated on thursday. But other than that I am clueless.
I do not know if I have a bus problem that causes problems with the sensors. Or I am having a sensor problem that causes errors with the bus?
I have not seen anybody else with bus problems for the heat pump?

 

[gitnewb]

This is a known issue. The problem is that you need to change all sensors on the same LIN bus with the newest part number. If there are two sensors with different part numbers on the same LIN bus it won't auto address. Follow this TSB: https://static.nhtsa.gov/odi/tsbs/2021/MC-10205423-0001.pdf

 

[f1geek]

This is a known issue. The problem is that you need to change all sensors on the same LIN bus with the newest part number. If there are two sensors with different part numbers on the same LIN bus it won't auto address. Follow this TSB: https://static.nhtsa.gov/odi/tsbs/2021/MC-10205423-0001.pdf

Great insight. Thanks! Hope this does the trick.

 

[Philipnjf]

This is a known issue. The problem is that you need to change all sensors on the same LIN bus with the newest part number. If there are two sensors with different part numbers on the same LIN bus it won't auto address. Follow this TSB: https://static.nhtsa.gov/odi/tsbs/2021/MC-10205423-0001.pdf

Thank you very much. This was very helpfull.
Although this will now cost 2 additional sensors and filling the system once again.

I do have 2 follow up questions.

1 should i still update the hvac software to 0203 and does this make any difference?

2 are there any cheap functioning sensors avalible? This is starting to get expensive.

Thank you.

 

[gitnewb]

I would update the HVAC software to 0203 or higher as there is a TSB about this already.



I don't know of any aftermarket sensors that can be used. If it was my money, I would find the cheapest OEM supplier for the part and go with that. If you go aftermarket and it fails on you, then you know how expensive it is to replace the refrigerant again to redo the job.

 

[Philipnjf]

Thank you very much. This was very helpfull.
Although this will now cost 2 additional sensors and filling the system once again.

I do have 2 follow up questions.

1 should i still update the hvac software to 0203 and does this make any difference?

2 are there any cheap functioning sensors avalible? This is starting to get expensive.

Thank you.

Is there any schematic to see the location of the sensors? Looking for sensor 5

 

[gitnewb]

Temp/pressure sensor 5 is G829 located here:

 

[Philipnjf]

Hi all.
Thank you very much. So I guess I found the mistake. As said 3 sensor where changed before I bought the car. The new sensors are E type. 2 of them working.
Well It just dawned on me that maybe the mechanic had just as hard a time as me to figure out the locations.
So took a picture of the sensor in the front right wing sensor 5. That one is the old type. Therefor I conclude they have changed the wrong sensor. I have ordered a new one and will update after replacement.
No I will not do it while the system is under pressure.

 

[gitnewb]

Don't forget also to connect a scan tool and open all the valves up when doing the extraction and refill of the refrigerant. Common mistake shops make because they don't understand how the e-golf works.

 

[Philipnjf]

I have vcds for it an for adress for the sensor.