Does replacing an old ABS pump require matching?

[Sadie]

Replacing an old ABS pump requires matching. Without proper matching, the ABS warning light will not turn off, and the part numbers must be consistent. The matching process can be efficiently completed using a 5054 tool. Additionally, both the ESP and tire pressure monitoring systems need to be configured to achieve perfect matching. How ABS works: During braking, ABS rapidly determines whether a wheel is locking up based on speed signals from each wheel speed sensor. It then closes the normally open input solenoid valve for the wheel that is starting to lock, maintaining the braking force. If the wheel continues to lock, the normally closed output solenoid valve opens, allowing brake pressure to rapidly decrease as the brake fluid flows directly to the reservoir, preventing the wheel from completely locking due to excessive braking force. This keeps the braking state at the optimal point (with a slip ratio S of 20%), ensuring the best braking performance and maximum driving safety. Classification of ABS: ABS is primarily categorized by channels. In ABS systems, brake lines that can independently regulate brake pressure are referred to as control channels. ABS systems are classified into four-channel, three-channel, two-channel, and one-channel configurations. One-channel ABS: Also known as single-channel ABS, it features a single brake pressure modulator in the rear wheel brake line and a wheel speed sensor installed on the rear axle differential (or one sensor on each rear wheel in some cases). Two-channel ABS: This configuration struggles to balance directional stability, steering control, and braking efficiency, and is rarely used today. Three-channel ABS: This system independently controls the two front wheels, while the two rear wheels are controlled together based on the select-low principle (i.e., both wheels are controlled by one channel to ensure the wheel with less traction does not lock), also known as hybrid control. Four-channel ABS: Equipped with four wheel speed sensors, this system has a separate brake pressure modulator in the brake line to each wheel, allowing independent control and forming a four-channel control configuration.