44500-47141 | Genuine Toyota® Brake Actuator Assembly 2005–2009 Toyota Prius

• Generates and controls brake pressure
  • Converts the driver's brake pedal input into hydraulic pressure.
  • Adjusts pressure sent to each wheel.
• Operates the ABS (Anti-lock Braking System)
  • Prevents wheels from locking during hard braking.
  • Improves steering control while braking.
• Supports stability and traction control
  • Can apply individual wheel brakes automatically to help maintain vehicle stability.
  • Works with traction control systems to reduce wheel spin.
• Manages brake assist functions
  • Detects emergency braking and can increase braking force.
• Coordinates regenerative braking (on hybrids and EVs)
  • Blends regenerative braking from the electric motor with conventional friction brakes.
  • Helps recover energy while maintaining smooth braking feel.

Warning Lights

• ABS light comes on.
• Brake warning light comes on.
• Traction control or stability control lights illuminate.
• Multiple warning lights appear simultaneously.

Unusual Noises

• Frequent buzzing, humming, or electric pump noises from under the hood.
• The pump runs every few seconds, even when you're not pressing the brake pedal.
• Clicking sounds from the actuator assembly.

Brake Pedal Problems

• Brake pedal feels hard and requires more effort.
• Brake pedal feels spongy or inconsistent.
• Pedal travel changes unexpectedly.
• Brake feel varies from stop to stop.

Braking Performance Issues

• Longer stopping distances.
• Reduced braking power.
• ABS activates unexpectedly at low speeds.
• Jerky or uneven braking.

Hybrid-Specific Symptoms

• Regenerative braking feels inconsistent.
• Sudden change in braking feel when slowing down.
• Reduced regenerative braking effectiveness.

Common Diagnostic Trouble Codes

On Toyota/Lexus hybrids, actuator failures often trigger codes such as:

• C1252
• C1253
• C1256
• C1345
• C1391 (often associated with an internal leak in the actuator)