P0526Fan Speed Sensor Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- Engine-driven fans with an electronically controlled viscous clutch (GM petrol SUVs and pick-ups 2004–2006, GM Duramax, Ford 6.7 L Power Stroke) have a Hall sensor reporting fan speed; the fan checks P0483, P0494 and P0495 need it. P0526 means no usable signal although the clutch is driven: GM Duramax below 500 rpm with fan duty at least 36 % for 2 s; the 6.6 L LML distinguishes a level stuck low or high; GM petrol V8s set it when no pulses arrive with the engine running. Type B, two trips. GM also reports a missing signal under P0526. A GM bulletin for 2011–2013 Duramax vans and pick-ups names loud fan noise and weak air conditioning at low speed.
- What you may notice
- Check engine light on
- Fan permanently on or off, loud fan noise
- Weak air conditioning at low speed, overheating under load
- Likely causes
- LikelyHall sensor at the fan clutch faulty
- PossibleWiring or connector (chafing at the shroud, corrosion)
- PossibleClutch not turning despite command
- RareEngine module or supply
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €80 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.