Fan Control Circuit
Indicates an issue with the engine cooling fan control circuit.
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 engine cooling fan isn't working right, which can cause the engine to overheat. It's usually a wiring or control issue.
What the computer is actually seeing
The ECM monitors the voltage levels in the fan control circuit and expects certain operational parameters. If the voltage is too low (below 10 volts) or too high (above 14 volts), it triggers this fault code depending on the fan state.
What a healthy reading looks like
Normal fan operation should see around 12-14 volts of supply voltage in a functioning circuit when activated.
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 at the fan for damage or corrosion. Look for loose connections.
- 22. Check the fan motor for continuity; it should show around 0.5 to 5 ohms resistance when tested.
- 33. Measure the voltage at the fan connector with the engine running; you should see 12-14 volts when the fan should be on. If not, continue checking the circuit.
- 44. If the voltage is present, test the fan by applying direct power to see if it operates. If it doesn't, replace the fan motor.
- 55. If the fan operates with direct power, check the signal wire from the ECM to the fan control; ensure the ECM is sending the right signal.
Common causes
- Open or shorted wiring in the fan control circuit
- Faulty cooling fan motor
- Defective engine control module (ECM)
- Poor connector contact at the fan or ECM
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not recommended to drive long distances, as overheating can lead to severe engine damage.
Will this code come back after clearing?
If the underlying issue isn't fixed, the code will typically return, especially if the fan continues to malfunction.
Why does this code sometimes pair with SPN 168?
SPN 168 relates to the fan speed sensor; if there's a fan control issue, it often leads to abnormal readings on the speed sensor as well.
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