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Common Problems and Reliability

• 1. Transmission Failure (CVT and Automatic Transmissions):

  Models Affected: C-HR, Avalon, Avalon Hybrid, 4Runner.

  • Fault Module: Continuously Variable Transmission (CVT), Torque Converter.
  • Issues: Gear slipping, loud whining/humming noises, delayed acceleration, sudden power loss, and complete transmission failure.
  • Cause: Defective torque converters, poor design of CVT systems, inadequate cooling, and metal debris in transmission fluid.
  • Solutions:
    • Replace or rebuild the transmission and torque converter.
    • Conduct regular transmission fluid checks and replacement.
    • Toyota has issued Technical Service Bulletins (TSBs) but no widespread recall.

• 2. Electrical System Malfunctions:

  Models Affected: Avalon, 4Runner, Camry, Corolla.

  • Fault Module: Engine Lubrication System, Piston Rings.
  • Issues: Rapid oil loss between oil changes, engine knocking, and eventual engine failure due to sludge buildup.
  • Cause: Defective piston rings and poor engine ventilation leading to oil burning and sludge accumulation.
  • Solutions:
    • Replace piston rings and clean the engine internals.
    • Toyota extended warranties for certain models but often requires oil consumption tests.

• 3. Unintended Acceleration:

  Models Affected: Avalon, Camry, Prius, 4Runner.

  • Fault Module: Electronic Throttle Control System (ETCS), Gas Pedal Assembly, Floor Mats.
  • Issues: Sudden and unintended acceleration without driver input, leading to loss of control.
  • Cause: Sticky accelerator pedals, pedal entrapment by floor mats, or faulty throttle software.
  • Solutions:
    • Recall to replace or modify accelerator pedals.
    • Update throttle control software.
    • Install brake override systems to prioritize braking over acceleration.

• 4. Brake System Malfunctions:

  Models Affected: Avalon, C-HR, 4Runner, Prius.

  • Fault Module: Brake Booster, ABS System, Electronic Parking Brake (EPB).
  • Issues: Reduced braking power, ABS failure, and the EPB failing to engage or disengage.
  • Cause: Faulty brake booster pumps, air in the brake lines, defective ABS modules, and software bugs in EPB.
  • Solutions:
    • Replace brake booster pumps and ABS modules.
    • Software updates for EPB.
    • Toyota has issued recalls for some models.

• 5. Airbag Deployment Failures:

  Models Affected: C-HR, Avalon Hybrid, Corolla, 4Runner.

  • Fault Module: Airbag Control Module, Crash Sensors.
  • Issues: Airbags fail to deploy during collisions, increasing injury risk.
  • Cause: Faulty crash sensors, defective airbag modules, or electrical issues in the deployment system.
  • Solutions:
    • Recall replacements for defective airbag components.
    • Inspection and replacement of malfunctioning sensors.

• 6. Fuel Pump Failures:

  Models Affected: Toyota 86, Avalon Hybrid, Camry, Corolla, RAV4.

  • Fault Module: Low-Pressure Fuel Pump.
  • Issues: Engine stalling, hesitation, and failure to start.
  • Cause: Defective impellers in the fuel pump degrade and cause the pump to stop working.
  • Solutions:
    • Toyota recalled millions of vehicles to replace faulty fuel pumps.
    • Fuel pump replacements are covered under warranty.

• 7. Power Door Lock Malfunctions:

  Models Affected: C-HR, 4Runner, Camry, RAV4.

  • Fault Module: Door Lock Actuators, Keyless Entry System.
  • Issues: Doors fail to lock/unlock using the key fob or interior buttons.
  • Cause: Faulty or worn-out door lock actuators and electrical malfunctions in the keyless entry system.
  • Solutions:
    • Replace malfunctioning door lock actuators.
    • Toyota has not issued recalls but dealers offer repairs.

• 8. Fuel System Issues:

  Models Affected: 4Runner, Tacoma, Tundra.

  • Fault Module: Vehicle Frame and Underbody Coating.
  • Issues: Severe frame rust leading to compromised structural integrity and component failures.
  • Cause: Inadequate corrosion protection, especially in cold climates with road salt.
  • Solutions:
    • Frame inspections and replacements under extended warranties.
    • Toyota initiated a limited frame replacement program for specific models.

• 9. Electrical and Sensor Failures:

  Models Affected: C-HR, Avalon Hybrid, Prius.

  • Fault Module: Pre-Collision System (PCS), Blind Spot Monitor, Instrument Cluster.
  • Issues: False alerts, system shutdowns, and malfunctioning sensors.
  • Cause: Sensor calibration issues, water intrusion, and software glitches.
  • Solutions:
    • Software updates and sensor recalibration.
    • Replacement of faulty modules when necessary.

• 10. Suspension and Steering Failures:

  Models Affected: Avensis, 4Runner, RAV4.

  • Fault Module: Rack and Pinion Steering, Suspension Components (Halfshaft, Ball Joints).
  • Issues: Loss of steering control, vibrations, and noisy suspension.
  • Cause: Premature wear of steering components, poor quality control in suspension assembly.
  • Solutions:
    • Replace damaged steering and suspension parts.
    • Toyota has issued TSBs but few recalls for these issues.