Standard Ignition ALS421 ABS Wheel Speed Sensor - Rear

ABS Wheel Speed Sensor for Volkswagen Passat

Standard Ignition ALS421 is an ABS wheel speed sensor for the rear wheel position on select Volkswagen Passat models. It uses a 43-inch harness and a rectangular 3-connector layout with male/female terminals for a direct-fit style replacement in the brake sensor circuit.

Key Features

• ABS wheel speed sensor for the rear wheel location
• 43-inch harness length for routing to the factory connection point
• Rectangular connector design with 3 connectors
• Male/female connector and terminal configuration
• Blade and pin terminal types
• No mounting hardware included

Detailed Description

Standard Ignition ALS421 is built for rear ABS wheel speed sensor service on 1998 Volkswagen Passat, 2001-2002 Volkswagen Passat, and 2003-2005 Volkswagen Passat models, including 2003-2005 Volkswagen Passat rear applications without self leveling headlights. This sensor monitors wheel speed data used by the ABS control system to help maintain braking stability and accurate wheel-speed feedback. The ALS421 part number is also a useful reference when cross-shopping replacement options for the same Volkswagen Passat rear sensor application.

This part cross-references Delphi SS20190 for the same application.

What It Helps Address

• ABS warning light triggered by a failed rear wheel speed sensor
• Intermittent wheel speed signal loss at the rear axle
• Brake system fault codes related to wheel speed input
• Erratic ABS operation caused by damaged sensor wiring or connector wear
• Loss of accurate wheel speed feedback on Volkswagen Passat rear applications

Installation Notes and Tips

Verify rear-position routing, connector style, and harness length before installation. Inspect the wheel-end connector, tone ring area, and wiring path for corrosion, abrasion, or debris that could affect signal quality. Confirm fitment for the exact Volkswagen Passat year and configuration, especially 2003-2005 models without self leveling headlights. The ALS421 part number should be matched to the vehicle application and connector layout before final assembly.

Quality Assurance

Standard Ignition replacement electrical components are built to meet application-specific fitment requirements for brake and sensor service. ALS421 is specified with the connector, terminal, and harness details needed for the listed Volkswagen Passat rear applications.