Sienna ABS and VSC Lights Due to Wheel Speed Sensor Fault

The most common cause for combined ABS and VSC dashboard lights is the failure of a wheel speed sensor, which prevents the computer from monitoring individual wheel rotation. To confirm this, connect a diagnostic scan tool capable of reading ABS/VSC codes and identify if a specific wheel location is reporting an invalid or missing signal. Physically inspect the sensor wiring at each wheel for frayed insulation or breakage, and check the sensor head for an accumulation of road debris or metallic dust that could obstruct the magnetic reading of the tone ring.

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