Vehicle Questions and Answers
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If you own a BMW, you might notice different warning lights and engine codes popping up on your dashboard. Typically, these lights signal that it's time for regular maintenance, like changing fluids, filters, or components. But if you see fault code 4121, it indicates a problem with power from the battery. To fix this, you should inspect the dme relay in the main fuse box under the hood for any shorts or damage. If a replacement is needed, expect to pay somewhere between $13 and $53 for the part.
In BMW, when you see Code 4121, it indicates a problem with the battery voltage.