2020 IS 300 ABS Light and Traction Control Warning On

ClearTheCode admin answer:

When both the ABS and Traction Control lights illuminate, it almost always points to an issue within the Anti-lock Braking System (ABS) or Vehicle Stability Control (VSC) system, as these systems are interconnected. The most common culprit is a wheel speed sensor.

Diagnostics & Next Steps:

1. Scan for Codes: Use an OBD-II scanner capable of reading ABS/VSC specific codes. Common codes include:
   • C0031-C0035: Wheel Speed Sensor (Front Left, Front Right, Rear Left, Rear Right) Circuit Malfunction.
   • C1201: Engine Control System Malfunction (often a secondary code).
   • C1238: Foreign Object Attached to Tip of Sensor.
2. Inspect Wheel Speed Sensors: If a specific wheel sensor code appears, visually inspect the sensor and its wiring at that wheel. Look for: * Physical damage to the sensor or wiring. * Corrosion on the connector. * Debris (dirt, metal shavings) on the sensor tip or tone ring (the toothed ring the sensor reads).
3. Brake Fluid Level: While less likely to cause both lights, ensure your brake fluid reservoir is at the correct level.

Common Causes:

• Faulty Wheel Speed Sensor: This is the most frequent cause. The sensor sends data to the ABS module, and if it fails, the system can't accurately monitor wheel speed.
• Damaged ABS Tone Ring: The tone ring (or reluctor ring) can get damaged or corroded, leading to incorrect readings.
• Wiring Harness Issues: A broken or corroded wire in the sensor's harness can interrupt the signal.
• ABS Module Failure: Less common, but the ABS control module itself can fail.

When to See a Shop:

While the car may still brake, the ABS and Traction Control systems are disabled, which can compromise safety, especially in emergency braking or slippery conditions. It's advisable to have your 2020 Lexus IS 300 inspected by a professional technician as soon as possible. They can accurately diagnose the specific sensor or component that has failed and perform the necessary repairs.