Originally Posted by Zat_Zuma

Wow I've just read about the ABS/VDC controls and what it uses for inputs and outputs.

My best guess is that the ECM is cutting the fuel to the injectors and partially closing the throttle bodies from a false reading from one of the sensors. This may be what is causing the lean condition to cause knock. Why this is happening when the VDC is turned off is anyone's guess. It may be as simple as a bad switch, to as complex as a faulty ECM controller. There should be lots of DTC codes to possibly show where the problem area is.

The check procedure for the ABS controller which is tied into the VDC controllers and the ECM fuel control is staggering and a consult computer is required. A simple check is to check the connectors on the ABS controller, located by the brake fluid reservoir, and the VDC on/off switch. Make sure they are seated properly.

I'm afraid to say if that doesn't cure it, a trip to the dealership is in order to troubleshoot the entire ABS system.