Econ light stays on fault code 00819

[tslag]

Hello,
I have searched this forum but didn't find an answer to my question.

I have a 2002 A6 4.2. The econ light on the climate control will come on and stay on about 5 minutes into driving, meaning I have no A/C. I had the car VAG'd today and here is the fault:
00819 - High Pressure Sensor (G65)
29-00 - Short to Ground

I found the following article on Ross-Tech:
http://wiki.ross-tech.com/index.php/00819

The recommended solutions are:
00819 - High Pressure Sensor (G65): Signal too Low
Possible Symptoms

* Climate Control stuck in ECON Mode

Possible Causes

* Insufficient Refrigerant Pressure
* Wiring/Connectors from/to High Pressure Sensor (G65) faulty
* High Pressure Sensor (G65) faulty

Possible Solutions

* Check Refrigerant Pressure
o Check Measuring Value Blocks (MVB)
* Check Wiring/Connectors from/to High Pressure Sensor (G65)
* Check High Pressure Sensor (G65)


My question is:
Should I have the system checked for low refrigerant before replacing the sensor? The 29-00 Short to ground from the fault code makes me think the actual sensor may be bad. Has anyone had this same code before? Any suggestions?

Thanks in advance.

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