Passat - B7On a friend’s car, a Passat B7 (3AA) the seat heaters didn’t work. So I connected to the car with VCDS to see if we could troubleshoot this.

I opened Control Module 9, Central Electronics:

VCDS | Select Control Module | 09 Central Electronics 

Then went to 7 Long Coding, and it turned out that the Seat Heating was not properly coded.

 

VCDS didn’t have a label file for this module but it should be Byte 22, Bit 2:

Central Electronics Coding | Byte 22 | Bit 2 | Seat Heating off

I changed it to:

Central Electronics Coding | Byte 22 | Bit 2 | Seat Heating on

And now the seat heaters were working again.

But the driver wondered why the seat heater level wasn’t remembered. I am not sure why this isn’t activated by default but it can be easily changed.

Go to Control Module 8, Auto HVAC:

VCDS | Select Control Module | 08 Auto HVAC

Then go to Adaptation, select channel “Storage of driver seat heater level” and select On as the New value:

VCDS | Select Control Module | 08 Auto HVAC | Adaptation | Storage of driver seat heater level

There’s not setting for the passenger seat though Sad smile