Chassis, generic

C062C Brake Booster Motor B Performance

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

C062C judges whether the second drive, B, of an electric brake booster moves as commanded; the circuit may be intact. Boosters like Bosch's iBooster turn motor torque through a three-stage gear into force on the master cylinder, and in redundant layouts such as a Hyundai Mobis design a dual-winding motor is fed by two power modules, each able to carry the whole current command alone if the other is declared failed. No maker documents C062C publicly. The yardstick is its twin C0594 for motor A: GM's 2016 hybrid tables flag a motor below 15 rad/s while more than 25 rad/s is requested, more than seven direction changes, or reverse rotation above 40 rad/s, within 0.15 s, Type A. With side B out, assist may still come from side A only.

Likely causes

Worn or damaged motor B, for example bearing or winding damage
Fault in the power module or driver stage feeding side B
Binding in gear stage or booster mechanism
Booster control software needing an update

Symptoms

  • Brake system or brake assist warning
  • Harder pedal or reduced assist in some situations
  • Driver assistance functions with automatic braking restricted

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–2,500
Time0.5–4 h

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

Parts involved

brake booster motor b

Related codes

C0594C0592C0593C058E

References: gsi.ext.gm.com, patents.google.com, bosch-mobility.com.