VCDS Reading Modules

[twoqu]

Its a good idea to check for voltage on the ecu K line, RT say that @9V is correct. If it has no voltage then it might be wiring related. I seem to recall that the later immo cars do not have a direct connection to the ecu unlike the L line. It goes from the post terminal to a connector and then to the immo box. It is designated T10. As suggested above you might have to verify continuity back to the ecu.
If you have been able to pull codes before and its just suddenly happened then you will have to be methodic. If it has happened after something you can recall such as the ecu being removed then it may well be something as simple as the pin in the connector being pushed out. So you will have to choose an end to start!

[twoqu]

Sounds like this guy is having similar problems. Look at post 5.

http://www.s2forum.com/forum/showthread.php?t=82444

[LGK6D]

Could it be the radio? I have a Becker Grand Prix

[twoqu]

Have you been able to pull codes since having the radio fitted?
There is some disagreement over whether our vehicles sufer from such issues.

[Dynasty]

Could it be the radio? I have a Becker Grand Prix

If there is a K - line wire in the radio connector, then yes. When plugging in an aftermarket radio make sure to isolate the K - line wire. K - line wires should only be connected to communication ports .