Knock sensor control limit, checking

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 Audi S8, 2003 Audi A8, 2002 Audi S8, 2002 Audi A8, and 2001 Audi S8. However, it is still accessible from the selected car via links, so may be relevant.

If the malfunction message "Knock Control to Limit Attained" is recorded in the DTC memory the following tests must be performed:

KNOCK SENSOR CONTROL LIMIT TROUBLESHOOTING

	Possible cause of malfunction	Corrective action
Malfunction message relating to all cylinders or malfunction message relating to all cylinders in one bank	Poor fuel quality	Change to higher quality fuel (see Owner's Manual)
	Incorrect tightening torque on knock sensor	Loosen knock sensor, then tighten to 20 Nm (15 ft lb)
	Knock sensor faulty Corrosion on connector	Check knock sensor. See KNOCK SENSOR (KS) 1 -G61- AND KNOCK SENSOR (KS) 2 -G66-, CHECKING .
	Knock sensor faulty Corrosion on connector
	Loose components on engine	Secure loose components
Malfunction message relating to one cylinder	Mechanical engine damage	Check compression pressure
Malfunction message relating to one cylinder	Loose components on engine	Secure loose components