ABS and Traction Control Lights On - 2017 LaCrosse

ClearTheCode admin answer: When both the ABS and Traction Control lights illuminate on your 2017 Buick LaCrosse, it typically indicates a fault within the Anti-lock Braking System (ABS) that also affects the Traction Control System, as they often share components and data.

Here are the most common causes:

1. Wheel Speed Sensors: These sensors monitor the rotational speed of each wheel. If one or more sensors are faulty, dirty, or have damaged wiring, the ABS module can't accurately determine wheel speed, triggering both lights. This is the most frequent cause.
2. ABS Module Failure: The ABS control module itself can fail. This is a more expensive repair but can happen, especially in older vehicles. Symptoms might include intermittent light illumination or specific diagnostic trouble codes (DTCs) pointing to the module.
3. Wiring/Connectors: Damaged or corroded wiring and connectors leading to the wheel speed sensors or the ABS module can interrupt signals, causing the system to fault.
4. Low Brake Fluid: While less common to trigger both lights simultaneously without other brake warnings, extremely low brake fluid can sometimes contribute to system warnings.

When to see a shop:

• Since you don't have an advanced scanner that reads ABS-specific codes, a professional diagnosis is highly recommended. Generic OBD-II scanners typically only read powertrain codes (P-codes), not chassis codes (C-codes) related to ABS.
• A shop can use a specialized scan tool to retrieve the exact C-code, which will pinpoint the faulty sensor or component.
• Ignoring these lights can compromise your vehicle's safety features, as ABS and Traction Control may not function correctly in emergency braking or slippery conditions. Prompt diagnosis ensures your safety systems are fully operational.