C0045 — Brake Pressure Sensor B

C0045: Brake Pressure Sensor B — what it means, the affected system and what to check before replacing parts.

Meaning, symptoms, causes and checks

Brake Pressure Sensor B. Basic catalogue definition; diagnostic details have not yet been reviewed.

Affected system: Chassis

Symptoms

  • Illumination of the anti-lock braking system warning indicator
  • Activation of traction control or electronic stability warning lights
  • Loss of ABS functionality during emergency braking maneuvers
  • Potential for wheel lock-up on slippery or wet road surfaces
  • Altered or unstable brake pedal feedback

Possible causes

  • Defective left rear wheel speed sensor
  • Frayed wiring or corroded sensor electrical connectors
  • Open or shorted electrical harness circuit
  • Internal failure of the ABS control module

What to check

  • Secure the vehicle on jack stands or a lift before inspecting the undercarriage
  • Perform a visual assessment of the left rear sensor and wiring for physical damage or corrosion
  • Use a diagnostic scan tool to clear the code and verify if the fault returns immediately
  • Measure the electrical resistance of the speed sensor using a multimeter to compare against factory specifications
  • Test the electrical continuity of the wiring harness from the sensor to the ABS control module
  • Evaluate the ABS module for faults if all sensor and wiring components perform within normal parameters

Also written as: C0045-00, C004500, CO045 (some scan tools add the fault-type byte, e.g. -00).