C0045 on Ford: How to Diagnose & Fix
Left Rear Wheel Speed Sensor Circuit
1 Ford model · 1 documented issue · $250-$500 repair
C0045 on Ford by model: symptoms, diagnosis and fix
1999-2007 Ford Focus (1st-generation Mk1 and Mk1.5) suffer from repeated rear wheel bearing failures, often within months of replacement. One Focus Fanatics owner reported the left rear wheel bearing failing 4 times in 7 months. Root cause is missing or degraded inboard spindle seals that allow brake dust and water into the bearing race, plus alignment drift (excessive negative camber or toe) accelerating wear. Ford acknowledged the seal design in owner communities but never issued a formal recall. Replacement requires the full hub assembly. The 2012-2018 Mk3 Focus has separate bearing issues with different root causes (not covered by this entry).
Common Symptoms
- Humming or growling noise from rear wheels that increases with speed
- Rumbling noise that changes pitch when turning (load shifts off bearing)
- Vibration felt through vehicle floor
- Uneven rear tire wear
- ABS warning light if bearing play affects wheel speed sensor
- Loose or wobbly feeling in rear end
- Grinding noise from rear at highway speeds
How to Fix
Replace the rear wheel bearing/hub assembly as a complete unit - the bearing is sealed and non-serviceable. RepairPal estimates $317-429 per side. When replacing, clean the knuckle bore thoroughly and apply anti-seize compound to prevent the new bearing from seizing in the housing (makes future replacement much easier). If the vehicle is in a salt-belt state, replace both rear bearings simultaneously - the other side will likely fail soon after.
Sources for this issue (1)
C0045 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does C0045 mean on a Ford?
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 Ford it is documented across 1 model: Focus.
What are the most common causes of C0045?
The most common causes of C0045 are: 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). The specific cause varies by vehicle.
How much does it cost to fix C0045 on a Ford?
Published repair estimates on Ford range from $250 to $500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for C0045 on a different make?
View C0045 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.