Jeep ABS Light On? How to Troubleshoot and Fix It

Is the ABS light on in your Jeep, or are you seeing a SERVICE ANTI-LOCK BRAKE SYSTEM message on the dashboard? In this video, we show you how to troubleshoot the ABS warning light step by step, what the most common causes are, and what you can check yourself before spending money at the dealer or replacing parts you don't need. When the ABS control module detects a fault, it disables antilock braking and turns on the ABS light. Your regular brakes still work, but ABS, traction control, electronic stability control (ESC), hill start assist, and trailer sway control may all be disabled. That is why the ABS light often comes on together with the traction control light, ESC light, or even the red brake warning light. COMMON CAUSES WE COVER: A failed wheel speed sensor or a sensor contaminated with metal debris on its magnetic tip, a cracked or rusted tone ring (reluctor ring) on the axle shaft or CV joint, a failing wheel bearing hub assembly with a built-in speed sensor encoder (very common on Jeeps with hub-mounted sensors), rust buildup pushing the sensor away from the tone ring and creating an air gap, chafed or broken sensor wiring at the strut or suspension travel points, corroded or water-damaged connectors, a weak battery or charging system causing low system voltage, internal ABS pump motor failure, a failing ABS control module, and even mismatched or incorrect tire sizes causing an implausible wheel speed signal. SYMPTOMS: ABS light on constantly or intermittently, ABS and traction control light on at the same time, ABS light comes on after driving a short distance, speedometer erratic or dropping to zero, ABS self-test grinding noise at low speed, ABS activating when braking gently on dry pavement, cruise control stops working, 4WD warning on some models. RELATED FAULT CODES: Wheel speed sensor circuit and performance codes: C0031, C0032 (left front), C0034, C0035 (right front), C0037, C0038 (left rear), C003A, C003B (right rear). Pump and module codes: C0020 (ABS pump motor), C2116 (pump motor supply voltage low), C1020 (ABS module internal). Voltage and communication codes: C2100 or C2101 (battery voltage low or high), U0121 (lost communication with ABS module), U0415 (invalid data received from ABS module), and C121C (torque request signal denied). A basic OBD2 code reader usually cannot access the ABS module, so you will need a full-system scanner such as the YOUCANIC UCAN-II to pull these chassis codes, view live wheel speed sensor data for all four wheels, and pinpoint exactly which sensor or circuit is dropping out instead of guessing and replacing parts. This guide applies to all popular Jeep models, including the Jeep Wrangler JK, JL, and TJ, Grand Cherokee WJ, WK, WK2, and WL, Cherokee KL and XJ, Renegade, Compass, Gladiator JT, Patriot, Liberty, and Commander. Since Jeep shares its ABS and brake electronics with other FCA / Stellantis vehicles, most of these steps also apply to Chrysler, Dodge, RAM, and Fiat models. Popular searches this video covers: Jeep ABS light on, how to fix ABS light Jeep, Service Anti-Lock Brake System Jeep, ABS and traction control light on Jeep, Jeep wheel speed sensor replacement, Jeep wheel bearing hub assembly ABS, tone ring rust ABS light, ABS light comes on and off Jeep, how to read ABS codes without dealer scanner, Jeep Wrangler ABS light on, Jeep Grand Cherokee ABS light on, Jeep Cherokee ABS light, ABS module repair Jeep, C0031, C0034, C0037, wheel speed sensor code, ABS pump failure symptoms, traction control light stays on. For more car repair guides, resources, and diagnostic tools, visit https://youcanic.com SUBSCRIBE for more Jeep diagnostics and DIY car repair videos!