ABS Wheel Speed Sensor A2215400117 for W221 rear left or rear right OE replacement designed to meet or exceed the performance and quality standards of the original equipment installed on your vehicle. This sensor delivers the same level of performance as your original part. Direct replacement: Installs seamlessly, just like the factory unit. No modification required. Reliable operation: Each sensor undergoes rigorous testing and inspection to ensure utmost reliability and quality. Compatibility and fit: Fits Mercedes W221, rear axle, usable on either left or right side. Mirrors the original connector and mounting points for a secure, accurate fit. Function and performance: Provides precise wheel speed data to the ABS and stability/traction control systems to maintain safe braking and vehicle control. Verification and quality: Engineered to OE specifications to ensure proper signal, timing, and response with the vehicle's ABS/ESP systems. 23 practical use scenarios Scenario 1: ABS or traction control warning light On in a W221. Replacing a faulty rear wheel speed sensor with this OE replacement restores system monitoring and braking stability. Scenario 2: After brake service or routine maintenance on a W221 with a mileage, replacing a worn sensor prevents intermittent ABS/ESP issues and helps ensure consistent braking performance. Scenario 3: Preparing a W221 for resale or longterm ownership. Replacing the rear left or right wheel speed sensor maintains original system reliability and reduces the risk of future sensorrelated faults.