You’ve probably seen it before. The ABS light comes on, the scan tool shows a wheel speed sensor code, and the parts cannon fires. A hub bearing gets replaced, a new sensor goes in. When that doesn’t work, the ABS module takes the blame. Meanwhile, the customer is still unhappy. In this video, we’ll dive into active wheel speed sensors so your shop avoids wasted parts and comebacks.
These sensors are the foundation of ABS, stability control, and ADAS systems, but they’re also misunderstood. They detect movement, but they also rely on precise electrical signals, tight mechanical tolerances, and software logic to tell the module what’s happening at the wheel. Technicians usually misdiagnose problems because they skip the basics.
Understanding Active Wheel Speed Sensors Codes And Common Failures
Wheel speed sensor codes fall into two categories: electrical circuit codes and erratic performance codes. Electrical codes are straightforward. Erratic performance codes are trickier, often caused by physical issues between the encoder ring and sensor tip.
Problems like bearing play, excessive air gaps, or corrosion on the tone ring can trigger dropouts the ABS module can’t interpret. That’s when false failures and unnecessary parts replacements start to pile up.
Smarter Diagnosis Tools And Tests
For tire shops and dealers, diagnosing active wheel speed sensors accurately is critical. Modern scan tools can graph all four wheel sensors in real time, showing you what the ABS module sees. A quick test drive with a cornering maneuver can reveal sudden drops in wheel speed that point to bearing movement or damaged encoder rings.
Technicians can reveal air gap issues or wiring faults by spinning a wheel while monitoring voltage before ordering a single part.
Build Trust Through Fundamentals
The bottom line? Start with the fundamentals. Inspect wiring, verify resistance and bias voltage, and use scan tool or scope data to confirm the signal. When in doubt, compare readings to the opposite wheel on the same axle.
Understanding how active wheel speed sensors function protects your reputation and builds customer trust.
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The post What You Should Know About Active Wheel Speed Sensors appeared first on Tire Review Magazine.
