C0045 on RAM
Left Rear Wheel Speed Sensor Circuit
C0045 on RAM vehicles indicates left rear wheel speed sensor circuit. Au7o has documented this code across 1 RAM model — most commonly on 1500. 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 RAM range from $200 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 RAM by Model
RAM 1500(1 issue)
- Front Wheel Bearing / Hub Assembly Failure (Humming/Growling Noise, ABS Light)2009-2018
4th-gen Ram 1500 front wheel bearing/hub assemblies wear out relatively early (some as low as ~50k miles), producing a humming or growling noise that rises with speed and changes with steering load. Because the wheel-speed sensor is integrated into the hub, a failing bearing frequently also sets an ABS/traction fault and light. It is one of the most common front-end noise complaints on these trucks.
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View C0045 across all makes →Frequently Asked Questions
What does C0045 mean on RAM?▼
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 RAM specifically, this code is documented across 1 model.
What causes C0045 on RAM vehicles?▼
Common causes on RAM: 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 RAM?▼
Repair costs on RAM range from $200 to $600, depending on the specific model and root cause.
Which RAM models have C0045 documented?▼
Au7o has documented C0045 on 1 RAM model: 1500.