Fan Control Circuit Shorted to Ground
The fan control circuit has a short circuit to ground detected.
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 trying to turn on the fan, but it thinks there's a problem because it sees a path to ground where there shouldn't be one.
What the computer is actually seeing
The engine control module (ECM) expects a certain voltage from the fan control circuit (typically around 0-5 volts). If it sees a voltage drop to 0 volts when it commands the fan on, it triggers this code.
What a healthy reading looks like
When the fan is commanded on, the voltage should be close to battery voltage (12-14 volts); during normal operation without a fault, it should be 0 volts when off.
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 the wiring and connectors for the fan control circuit for any visible damage or corrosion. If found, repair as needed and retest.
- 22. Disconnect the fan motor and check the resistance of the motor. If it's out of specification (usually under 10 ohms depending on make/model), replace the motor.
- 33. Check the fan control relay operation by swapping it with a known good one. If the code clears, replace the relay.
Common causes
- Damaged wiring or connectors in the fan control circuit
- Faulty fan control relay
- Shorted fan motor
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not recommended as it may lead to overheating or engine damage, so have it checked soon.
Will this code come back after clearing it?
If the fault is still present, it will return after clearing.
Why does this code sometimes pair with SPN 3198?
SPN 3198 relates to the fan being commanded on but not operating, which can be a consequence of the same underlying issue in the control circuit.
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