FMI 3 - Data Erroneous - 12V Power Supply Voltage Out of Range
This code indicates a voltage input issue with the electronic device.
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 computer is getting mixed signals about the voltage it should be receiving, which could mean it's higher or lower than expected, making it confused about the engine's state.
What the computer is actually seeing
The ECM (Engine Control Module) detects that the power supply voltage is either too high (over 16 volts) or too low (under 10 volts) when it should be stable around 12 volts for proper operation.
What a healthy reading looks like
12V to 14V under normal operation.
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. Inspect battery voltage with a multimeter. Should be between 12V and 14V. If not, charge the battery or replace it.
- 22. Check all ground connections for corrosion or looseness. Clean and tighten as necessary.
- 33. Inspect the wiring harness and connectors related to the component giving the fault. Look for frays, breaks, or corrosion.
- 44. With the ignition on, verify the voltage at the affected component’s power supply wire. Should be stable between 12V and 14V. If fluctuating, trace back to the source.
- 55. If all connections and the battery are fine, connect a scan tool and look for other fault codes. If this is the only code, consider testing or replacing the ECM.
Common causes
- Faulty wiring or connectors
- Failing battery
- Faulty ECM or module
- Corroded grounds
- Short circuits in the power supply harness
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code present?
It's not recommended, as it can lead to significant engine issues.
Will this code come back after reset?
If the underlying issue isn’t resolved, the code will likely return.
Why does SPN 4044 show up with other codes?
SPN 4044 can trigger with codes related to power supply issues, indicating broader electrical problems.
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