Chassis, generic

C058D Brake Booster Motor B Position Sensor Circuit High

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

C058D is set when a signal of motor B's position sensor exceeds its upper limit, for example because a sensor line touches supply voltage or the sensor ground has opened. No manufacturer documents C058D publicly; the range/performance case of the same sensor is C058E, which Stellantis lists for the Jeep Wagoneer eBooster. A short to battery in a resolver path pushes the evaluated signal to its ceiling, as Hitachi's patent explains. Bosch's booster patent outlines what a controller can still do when rotor position feedback is lost: drive the motor open-loop with capped speed and limited speed changes. Depending on the design, the module therefore continues with motor A, runs a degraded mode or switches assist off entirely.

Likely causes

Signal line of sensor B shorted to supply or battery voltage
Open ground of sensor B lifting the signal
Internal fault of sensor B in the booster

Symptoms

  • Brake system warning and message
  • Assist weaker or switched off depending on design

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–2,800
Time0.5–4 h

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

Parts involved

booster motor b pos sensorsensor wiring

Related codes

C058BC058CC058EC0589

References: patents.google.com, patents.google.com, static.nhtsa.gov.