C0586 code meaning
Brake Booster Motor B Phase U-V-W Circuit Range/Performance
What C0586 means
C0586 is set when the B drive stage of the booster motor is electrically connected but behaves implausibly: phase currents that do not match the command, a transistor pair conducting at once, or a bridge driver that fails its start-up self-test. Nobody publishes limits for side B. GM's tests for motor A under C0582 – more than 150 A in a cross-switching test, an idle phase not at 1.65 V – show what such a check looks like. TI's DRV3245Q-Q1, designed for electric brake and brake assist, adds shoot-through prevention and gate-source monitoring for the same purpose. In a dual-winding motor like the Hyundai Mobis one, diagnostics classify each power module as healthy or failed; the failed one is switched off, so the driver may notice a weaker or slower pedal response.
C0586 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C0586
- Brake warning or service message
- Pedal response weaker or slower than usual
Common causes of C0586
- PossibleBridge driver of channel B failing its self-test
- PossibleCurrent measurement of channel B drifting, currents no longer match the command
- Less likelyControl unit software issue, resolved by update where available
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Brake booster motor b
What each part of C0586 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 86 | The exact fault in that area. |
What to do next
- Note C0586 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 C0586
What does C0586 mean?
C0586 means "Brake Booster Motor B Phase U-V-W Circuit Range/Performance". C0586 is set when the B drive stage of the booster motor is electrically connected but behaves implausibly: phase currents that do not match the command, a transistor pair conducting at once, or a bridge driver that fails its start-up self-test. It is a generic code, so it means the same on every make.
Is it safe to drive with C0586?
Drive gently and only to a workshop. With C0586 the car can go into limp mode (reduced power) to protect itself.
Will C0586 fail an emissions test?
C0586 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 C0586 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will C0586 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.