Help protect your engine from damaging detonation with the Standard Ignition Ignition Knock (Detonation) Sensor KS221. It installs as a direct-fit replacement across a range of 1.8L four-cylinder and 2.7L/3.0L V6 Audi and Volkswagen models, including the 2001-2006 Audi A4, 2001-2006 Audi A4 Quattro, 2002-2005 Audi A6, 2003-2004 Audi A6 Quattro, 2003-2005 Audi Allroad Quattro, and 2000-2005 Volkswagen Passat.
A knock sensor picks up the high-frequency vibrations produced by abnormal combustion (knock/detonation) and sends a voltage signal to the engine control module, which can then adjust ignition timing. If a failed knock sensor is the cause of a stored knock-related trouble code, this unit replaces it.
- Wide response range: designed to respond to knock frequencies up to 1000 Hz to accommodate shifts in engine knock across varied operating conditions.
- 100% tested: every unit is checked with an accelerometer vibration test for reliable operation.
- Monitored output: an automated data-acquisition system verifies appropriate voltage output at the specified frequency range.
- Bolt-on design: oval plug-in connector with three male blade terminals; mounting hardware is not included.
Some listed applications use two sensors per engine, so confirm the quantity your vehicle needs in the Buyer's Guide tab. Country of origin: Italy.
Interchange: 06C905377 · S8821 · SU6306 · DKS661 · Manufacturer part number KS221
Fitment: 2001-2006 Audi A4 [L4-1.8L]; 2002-2005 Audi A4 [V6-3.0L]; 2001-2005 Audi A4 Quattro [L4-1.8L]; 2002-2006 Audi A4 Quattro [V6-3.0L]; 2002-2005 Audi A6 [V6-3.0L]; 2003-2004 Audi A6 Quattro [V6-2.7L]; 2002-2004 Audi A6 Quattro [V6-3.0L]; 2003-2005 Audi Allroad Quattro [V6-2.7L]; 2000-2005 Volkswagen Passat [L4-1.8L].
This part cross-references / interchanges with the following part numbers:
06C905377, S8821, SU6306, DKS661, KS221
