Section 2 (Anti-Lock Brake System - With TCS): Self-Diagnostics: Pre-Inspection
WARNING: This page is about a different car, the 1996 Subaru Legacy and 1995 Subaru Legacy. However, it is still accessible from the selected car via links, so may be relevant.
Before fault testing ABS, ensure battery voltage, brake fluid level, tire specification, tire wear and tire air pressure are okay. Check for brake fluid leakage. Ensure brake drag is minimal and brake pads and rotors are okay.