Question 1

Headlights flickering or turning off (2010-2011 Prius)

Accepted Answer

The HID headlights on some 2010-2011 Prius models can flicker or turn off while driving, reducing visibility at night. Toyota offered a warranty enhancement to replace the affected parts.

Question 2

Weak 12V auxiliary battery (1.8 Hybrid)

Accepted Answer

On electric and hybrid vehicles, the 12V auxiliary battery powers the startup electronics; when it weakens the car may not go into Ready mode, show random warnings or fail to charge. It is more common with infrequent use and after 4-6 years.

Question 3

Hybrid battery degradation with age

Accepted Answer

The NiMH hybrid battery loses capacity with age, usually after 10 years or around 150,000 miles (240,000 km). Signs include a check hybrid system warning, poorer fuel economy and the engine running more often.

Question 4

Inverter coolant pump failure

Accepted Answer

The electric pump that cools the hybrid inverter can fail, triggering a check hybrid system warning and reduced power to protect the inverter. Checking the inverter coolant circuit during service is recommended.

Question 5

EGR cooler clogging and head gasket failure (3rd gen Prius)

Accepted Answer

On the 3rd gen Prius 1.8 Hybrid, the EGR cooler and intake can clog with carbon, causing misfires and shaking; ignored, it often leads to a head gasket failure and coolant loss. Preventive cleaning is recommended around 100,000-150,000 miles (160,000-240,000 km).

Toyota PriusPrius 3rd Gen

Known issues and common problems

Toyota PriusPrius 3rd Gen

Known issues and common problems

Headlights flickering or turning off (2010-2011 Prius)1 solutionsMedium

Weak 12V auxiliary battery (1.8 Hybrid)1 solutionsLow

Hybrid battery degradation with ageat 240000 km · 1 solutionsMedium

Inverter coolant pump failureat 160000 km · 1 solutionsMedium

EGR cooler clogging and head gasket failure (3rd gen Prius)at 200000 km · 1 solutionsHigh