OBD-II code · Powertrain (generic)
P0494 Fan 1 Underspeed
Cooling fan 1 is rotating slower than commanded. The ECU sees the tachometer feedback below the expected window for the requested duty cycle - usually a worn fan motor, a high-resistance harness or feed, or a partially seized impeller.
Is it safe to drive with P0494?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyFan 1 motor worn or brushes degraded
- PossibleHigh contact resistance in feed
- Less likelyFan impeller seized or blocked
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.8–2 h
- Emissions test
- Usually unaffected
- Parts involved
- Cooling Fan 1, Fan Motor 1, Fan Speed Sensor 1
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.