B0186 code meaning
Front Blower Motor Speed Performance
What B0186 means
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.
B0186 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.3 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of B0186
- Blower speed does not match the selected stage or fluctuates
- Fan stops and restarts after a pause, sometimes with a grinding noise
Common causes of B0186
- Most likelyLeaves or other debris drawn in through the air intake, braking or jamming the fan wheel
- PossibleWorn blower motor bearings or brushes, motor runs slowly or stalls
- Less likelyHeavily clogged cabin filter loading the motor
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Blower motorBlower resistorCabin air filter
What each part of B0186 means
| B | Body system: airbags, seat belts, power seats, lights and climate control. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 86 | The exact fault in that area. |
What to do next
- Note B0186 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about B0186
What does B0186 mean?
B0186 means "Front Blower Motor Speed Performance". B0186 is not in the publicly available J2012 lists, and no manufacturer uses it for front blower speed. It is a generic code, so it means the same on every make.
Is it safe to drive with B0186?
B0186 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will B0186 fail an emissions test?
B0186 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is B0186 to fix?
Difficulty: medium. A typical repair takes 0.3 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will B0186 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.