Fan Performance Problem
The cooling fan is not operating properly as detected by the engine control module (ECM).
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 checks if the cooling fan is running when it should be. If it’s not moving enough air or not running at all, the code triggers.
What the computer is actually seeing
The ECM monitors the voltage signal from the cooling fan control circuit. It expects a certain voltage drop when the fan is activated, typically around 12V when on. If it sees little to no change, it flags an issue.
What a healthy reading looks like
Fan operation should show 12V to 14V when the fan is commanded on; no more than 5V 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. Check the fan wiring and connector for damage or corrosion. Clear any faults and retest. If the code returns, proceed.
- 22. Measure the voltage at the fan connector while the fan is commanded on. Expect 12V to 14V. If not, continue to step 3.
- 33. Check the fan relay by testing the ground side control or swapping with a known good relay. If the fan starts working, replace the relay.
- 44. If the fan still doesn’t operate with good power, replace the cooling fan assembly. Confirm operation afterwards.
- 55. If replacing the fan does not resolve the issue, consider testing or replacing the ECM.
Common causes
- Faulty cooling fan
- Damaged wiring or connector
- Faulty fan relay
- Faulty ECM
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's safe to drive short distances, but engine overheating could occur, so get it fixed soon.
Will this problem come back?
If you don't fix the underlying issue, yes, it can return.
Why does it pair with other fan codes?
They often indicate common wiring issues or fan and relay failures.
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