P0494
PowertrainCooling Fanmoderate severityCooling Fan Speed Low
What P0494 Means
The PCM has detected that the cooling fan speed is lower than expected. Reduced fan speed can cause the engine to overheat under load.
Symptoms
- Engine overheating
- Slow-running cooling fan
- Poor AC cooling
Common Causes
- Failing cooling fan motor
- Faulty fan control module
- Poor power or ground connection
- Damaged wiring
Diagnostic Steps
- Scan for stored codes
- Monitor actual fan speed data
- Check fan power and ground
- Test fan motor and module
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ANCEL AD410 →
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Serious DIY~$100
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Autel MaxiCOM MK808S →
Bidirectional tests, service resets, all systems.
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Pro diagnostics$1,500+
Autel MaxiSys MS906 Pro →
Full-system pro platform — topology mapping, ECU coding, the works.
✓ Autel official store
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