P0528 Fan Speed Sensor Circuit No Signal

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. P0528 means no pulses arrive from the sensor although the fan should be turning. No manufacturer document available to us uses P0528 – GM detects exactly this state (fan below 4 rpm with the engine running) but reports it as P0526. CARB requires input components to be checked for open and short circuits.

Likely causes

Symptoms

• Check engine light (depending on the maker)
• Fan permanently on or not at all
• Tendency to overheat

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: law.cornell.edu, gsi.ext.gm.com.