Body, generic

B0186 Front Blower Motor Speed Performance

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

B0186 is not in the publicly available J2012 lists, and no manufacturer uses it for front blower speed. Saab assigns it to the solar sensor of the 9-3: B0186 01 is a short to B+ in that circuit, after which the climate control assumes cloudy weather. A speed performance fault, as the title puts it, differs from the circuit faults B0181 and B0283: the wiring is intact, but the fan does not turn at the commanded speed. Denso's patent US10300764B2 shows how a blower control module checks this with a Hall sensor. If the rotor has not moved after about 2.7 s it reports a locked rotor to the climate module, power is cut and a in one example a restart follows after 20 s, five times at most until the next start. US5554913A names the classic cause: foreign objects sucked into the intake jam the wheel.

Likely causes

Leaves or other debris drawn in through the air intake, braking or jamming the fan wheel
Worn blower motor bearings or brushes, motor runs slowly or stalls
Heavily clogged cabin filter loading the motor

Symptoms

  • Blower speed does not match the selected stage or fluctuates
  • Fan stops and restarts after a pause, sometimes with a grinding noise

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–350
Time0.3–2 h

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

Parts involved

blower motorblower resistorcabin air filter

Related codes

B0181B0283B0184

References: saabwisonline.com, patents.google.com, patents.google.com.