FMI 2 - Low Side Short to Ground
Indicates a low side short circuit to ground in the system.
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 sees an electrical problem where the circuit is connecting directly to ground instead of going through the sensor, which causes incorrect readings or stops the sensor from working at all.
What the computer is actually seeing
The engine control module (ECM) detects that the voltage from a specific input is at 0 volts when it should be higher (normally around 5 volts for many sensors).
What a healthy reading looks like
Expected voltage should be between 0.5V to 4.5V depending on the sensor type.
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 wiring and connectors for damage or corrosion—look for frays, shorts, or loose connections.
- 22. Use a multimeter to check voltage at the sensor connector—expected voltage should be 0.5V to 4.5V. Is the voltage outside this range?
- 33. If the voltage is 0V, disconnect the sensor and check the harness with the multimeter again. Does the voltage change to normal values?
- 44. If there’s still 0V, trace the circuit for shorts to ground using a wiring diagram. Found a short?
- 55. If normal voltage is found with the sensor disconnected, replace the sensor. If not, continue inspecting the wiring back to the ECM.
Common causes
- Damaged wiring harness leading to a short circuit
- Faulty sensor causing incorrect voltage output
- Poor connection or corrosion at connector points
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; you can drive, but fix it soon to avoid further issues.
Will this code come back after clearing?
If the issue isn't fixed, yes, it will likely return.
Why does this code sometimes pair with SPN 31?
Both codes indicate electrical issues in related circuits, often from a common fault.
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