Brake Pad Wear Sensor Circuit Malfunction
What does C0145 mean?
The C0145 code means the vehicle's onboard diagnostic system has detected: Brake Pad Wear Sensor Circuit Malfunction. This is a moderate severity code.
Common Symptoms
- Brake pad wear warning light on
- Service brakes message on dashboard
- Warning light on despite new brake pads
- Brake pad indicator stays on after pad replacement
- Brake pad thickness display shows error
Probable Causes (Ranked by Likelihood)
- Worn brake pad wear sensor wire Very High
- Brake pad wear sensor not replaced with new pads High
- Corroded wear sensor connector Moderate
- Wiring fault to brake pad sensor Low
Step-by-Step Diagnostic Procedure
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Visually inspect brake pad thickness
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Check brake pad wear sensor wire for damage
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Verify wear sensor was replaced during last brake service
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Test sensor circuit continuity
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Inspect sensor connector for corrosion
Frequently Asked Questions
What is a brake pad wear sensor?
It is a thin wire embedded in the brake pad that contacts the rotor when the pad wears to a minimum thickness, completing a circuit that triggers the dashboard warning light.
Do all vehicles have brake pad wear sensors?
No. They are primarily found on European vehicles like BMW, Mercedes-Benz, Audi, and Volkswagen. Most Japanese and American vehicles rely on a metal tab that produces a squealing sound instead.
Should wear sensors be replaced every time brake pads are changed?
Yes. Wear sensors are one-time-use components. Once the wire has been worn through by the rotor, it must be replaced with new pads to reset the warning system.