Electronic Power Steering System Voltage High
What does C0249 mean?
The C0249 code means the vehicle's onboard diagnostic system has detected: Electronic Power Steering System Voltage High. This is a moderate severity code.
Common Symptoms
- Power steering warning light on
- EPS warning message on dashboard
- Steering assist may be reduced
- Electrical system symptoms like flickering lights
- Battery overcharging signs
Probable Causes (Ranked by Likelihood)
- Overcharging alternator producing excessive voltage Very High
- Faulty voltage regulator in the alternator High
- Poor ground connection causing voltage measurement error Moderate
- Battery fault allowing voltage spikes Moderate
- EPS module internal voltage sensing error Low
Step-by-Step Diagnostic Procedure
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Test alternator output voltage -- should not exceed 14.8V at the battery
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Check the voltage regulator function by monitoring voltage under varying loads
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Inspect all ground connections for the EPS system
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Test the battery for a shorted cell or other internal faults
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Monitor system voltage with a scan tool during various driving conditions
Frequently Asked Questions
How much voltage is too high for EPS?
Most EPS systems are designed to operate between 10V and 16V. Sustained voltage above 16V can damage the EPS module electronics and trigger a high voltage code.
Can an overcharging alternator damage my EPS?
Yes. Excessive voltage can damage the sensitive electronics in the EPS control module and motor driver circuits. A faulty alternator should be replaced promptly to prevent expensive damage.
Is this related to a battery problem?
It can be. A battery with an internal short or dead cell can cause the alternator to overcompensate, producing higher-than-normal voltage. Testing both the battery and alternator is important.