Delphi AS10251 Ignition Knock (Detonation) Sensor

Ignition Knock Sensor for BMW Applications

Delphi AS10251 is an ignition knock (detonation) sensor built for BMW engines that require accurate knock detection and stable engine management feedback. It is a direct-fit sensor solution for a wide range of BMW 3 Series, 5 Series, X Series, M models, and select i3 applications.

Delphi calibrates and validates its sensors to OE standards, helping deliver consistent readings for the engine control system. This part number, AS10251, is designed for vehicles that rely on precise detonation sensing to manage timing and protect performance.

• Ignition knock (detonation) sensor for engine knock detection
• Pin terminal type with 1 rectangular male connector
• 2 male terminals for OE-style electrical connection
• Package contents: sensor only
• Delphi OE-developed and OE-calibrated sensor design
• Part number AS10251 for BMW fitments

Detailed Product Information

Compatible With BMW 750i xDrive, 2012-2021; Alpina XB7, 2021; i3, 2014-2021; i3s, 2018-2021; M5, 2013-2016 and 2018-2021; M550i xDrive, 2018-2021; M8 Gran Coupe, 2020-2021; M850i xDrive, 2019-2021; M850i xDrive Gran Coupe, 2020-2021; X5, 2011-2021; X6, 2011-2021; X7, 2019-2021; M8, 2020; 650i Gran Coupe, 2013-2019; 650i xDrive Gran Coupe, 2013-2019; 750i, 2012-2019; M6 Gran Coupe, 2014-2019; 320i, 2013-2018; 320i xDrive, 2013-2018; 650i, 2012-2018; 650i xDrive, 2012-2018; M6, 2012-2018; X4, 2015-2018; 550i GT xDrive, 2011-2017; X3, 2013-2017; 228i, 2014-2016; 228i xDrive, 2015-2016; 328i, 2013-2016; 328i GT xDrive, 2014-2016; 328i xDrive, 2013-2016; 428i, 2014-2016; 428i Gran Coupe, 2015-2016; 428i xDrive, 2014-2016; 428i xDrive Gran Coupe, 2015-2016; 528i, 2012-2016; 528i xDrive, 2012-2016; 550i, 2011-2016; 550i xDrive, 2011-2016; Z4, 2012-2016; 550i GT, 2011-2015; 750Li, 2012-2015; 750Li xDrive, 2012-2015; X1, 2013-2015.

This part cross-references Standard Ignition KS397 for the same application.

Common Problems This Sensor Can Address

• Knock sensor fault codes related to detonation monitoring
• Rough running caused by inaccurate engine timing feedback
• Reduced engine response from a failing knock sensor signal
• Check engine light concerns tied to knock sensor circuit issues
• Driveability complaints on BMW engines that depend on precise knock detection

Installation Notes and Tips

Verify connector shape, terminal count, and mounting location before installation. AS10251 uses a single rectangular male connector with two male terminals and does not include mounting hardware, so reuse or source any required fasteners separately.

For best results, inspect the harness connector for corrosion, damaged pins, or oil intrusion before replacing the sensor. Clear diagnostic trouble codes after installation and confirm the repair with a road test and scan tool verification.

Quality Assurance

Delphi backs this sensor with OE development and product validation methods, and each sensor is tested and calibrated to OE standards for accurate readings. That level of calibration helps support consistent engine management performance and reduces repeat repairs.