The Technical Definition: The Anti-Lock Brake System (ABS) module detects a mismatch between its internal settings and the vehicle's master configuration (such as tire size or axle gear ratio) stored in the body or engine computers.

Common Symptoms: The ABS and Traction Control warning lights will instantly illuminate, disabling these safety systems.

Typical Fix: On Wranglers, this is almost always caused by installing larger aftermarket tires or changing axle gears without recalibrating the vehicle's computer. The fix requires a software update using an advanced scan tool like J-Scan, AlfaOBD, or a dealer's wiTECH tool to input the correct tire size or gear ratio.