Can a weak o r failing 12V battery affect the Prius power steering?

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Can a weak o r failing 12V battery affect the Prius power steering?

Since the EPS system relies on electrical power, a low o r failing 12V battery can sometimes cause steering problems. How can Prius owners check if their battery is affecting the steering system?

Lubaba asked on 14 Feb 2025 16:55:29 pm

1 Answer

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Car Mechanic Expert - on 14 Feb 2025 16:59:48 pm

Yes, a weak o r failing 12V battery can cause issues with the power steering in the Prius, as the EPS system relies on the 12V battery for electrical power. Symptoms of this include:

Stiff o r unresponsive steering: If the battery voltage is low, the EPS motor won’t receive enough power to assist with steering.
Sudden loss of power steering assist: This could happen if the 12V battery fails completely o r isn’t providing stable voltage.
Dashboard warning lights: The “check hybrid system” o r 12V battery warning may appear, indicating a power loss to the EPS system.

How to check:

Test the 12V battery voltage it should be around 12.6V when fully charged.
If the voltage is below 12V, consider replacing the battery, as it may be causing steering-related issues.