Redundant Electronic Control Unit Over Voltage
This code indicates an over-voltage condition in a redundant electronic control unit (ECU).
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The ECU, which controls various vehicle functions, is detecting a higher than normal voltage, over 16 volts, likely due to a wiring issue or a faulty component.
What the computer is actually seeing
Voltage readings above the normal range, usually exceeding 16 volts, indicating an over-voltage condition in the control circuitry.
What a healthy reading looks like
Nominal voltage should be between 12.5 to 14.5 volts with the engine running and no loads exceeding 16 volts during peak conditions.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check battery voltage; should be between 12.5 - 14.5 volts with engine running.
- 22. Inspect wiring and connectors for damage; look for corrosion or loose connections.
- 33. Test the voltage output at the alternator; it should not exceed 14.5 volts under normal operation.
- 44. If all checks are good, connect a scan tool to see if the code returns under different loads (like headlights, HVAC on).
- 55. If voltage is still high with normal operation, consider checking or replacing the ECU.
Common causes
- Faulty wiring or connector delivering too much voltage
- Defective ECU or redundant ECU functionality
- High voltage from the alternator
- Weak battery or battery management issues
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It can be, but it may lead to further electrical issues or component damage. Address it soon.
Will this code come back after clearing?
Yes, if the underlying issue isn’t resolved, it will likely return.
Why does this code appear with high current codes?
High voltage can cause increased current draw, leading to related fault codes.
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