C0045 on Subaru
Left Rear Wheel Speed Sensor Circuit
C0045 on Subaru vehicles indicates left rear wheel speed sensor circuit. Au7o has documented this code across 1 Subaru model — most commonly on Forester. This is a brake/ABS-system code. Each wheel has a speed sensor that tells the anti-lock brake (ABS), traction control, and stability systems how fast that wheel is turning. C0045 means the ABS module has detected an electrical problem in the circuit for the left rear wheel speed sensor — such as an open, short, or signal that's missing or out of range. As a result you'll typically see the ABS and traction/stability warning lights, and those safety features may be temporarily disabled even though your normal brakes still work. Typical repair costs on Subaru range from $250 to $600, depending on the specific model and root cause.
Common Causes of C0045
- •Failed left rear wheel speed sensor
- •Damaged, corroded or disconnected sensor wiring/connector
- •Damaged or contaminated tone/reluctor ring (rust, debris, missing teeth)
- •Excessive air gap between sensor and tone ring
- •Wheel bearing wear affecting the sensor (on bearing-integrated sensors)
- •Water intrusion or corrosion in the connector
- •Faulty ABS control module (less common)
C0045 on Subaru by Model
Subaru Forester(1 issue)
- Premature Front and Rear Wheel Bearing/Hub Failure (Faulty Backing Plate Design)2009-2018
Forester wheel bearings (both front and rear hub assemblies) fail prematurely, often well before 100,000 miles. The most consistent symptom is a low-pitched grinding, humming or 'airplane' droning noise from the affected corner that grows louder with speed; rear bearing wear is often felt as a vibration under the seats. The noise typically changes pitch or volume during a left/right lane-change maneuver (which distinguishes it from differential whine). Subaru acknowledged a contributing root cause: unevenness/distortion of the bearing backing plate surface affects hub/bearing concentricity after the axle nut is torqued, allowing a 'howling' bearing to develop over time. Water/dirt contamination from failed seals and improper axle-nut torque accelerate the wear. Subaru issued a service bulletin acknowledging the rear bearing/backing-plate concern.
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What does C0045 mean on Subaru?▼
C0045 stands for "Left Rear Wheel Speed Sensor Circuit." This is a brake/ABS-system code. Each wheel has a speed sensor that tells the anti-lock brake (ABS), traction control, and stability systems how fast that wheel is turning. C0045 means the ABS module has detected an electrical problem in the circuit for the left rear wheel speed sensor — such as an open, short, or signal that's missing or out of range. As a result you'll typically see the ABS and traction/stability warning lights, and those safety features may be temporarily disabled even though your normal brakes still work. On Subaru specifically, this code is documented across 1 model.
What causes C0045 on Subaru vehicles?▼
Common causes on Subaru: Failed left rear wheel speed sensor, Damaged, corroded or disconnected sensor wiring/connector, Damaged or contaminated tone/reluctor ring (rust, debris, missing teeth), Excessive air gap between sensor and tone ring, Wheel bearing wear affecting the sensor (on bearing-integrated sensors). Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix C0045 on a Subaru?▼
Repair costs on Subaru range from $250 to $600, depending on the specific model and root cause.
Which Subaru models have C0045 documented?▼
Au7o has documented C0045 on 1 Subaru model: Forester.