Chassis, generic

C058E Brake Booster Motor B Position Sensor Circuit Range/Performance

Check engine lightOn
EmissionsNot relevant
Drive cycleRequired
Limp modePossible

C058E concerns a second rotor angle channel of the electric booster motor whose readings are electrically valid but not believable. In GM's 2019 integrated brake control unit this is MPS2, a SENT sensor checked against the faster SPI sensor MPS1 of the same motor: a gap above 2° plus a 3° speed allowance, opposite directions or a changed rest offset for 100 ms set it, Type A with MIL. GM's PIT5638 series for the 2019 Silverado and Sierra 1500 covers cases where the cluster showed Service Brake Assist and the pedal turned hard; the fix was new BSCM calibration, and the ECM adds P25A2. Stellantis names C058E for the eBooster of the 2022–25 Wagoneer and Grand Wagoneer; if it returns after the revised test, BSCM and booster are replaced as a pair.

Likely causes

Brake control module calibration causing false correlation faults (GM PIT5638)
Second rotor position sensor in the booster drifting or failing
Fault inside the brake control module or eBooster unit (replaced together)
Poor contact in the booster sensor connector

Symptoms

  • Service Brake Assist message in the instrument cluster
  • Hard brake pedal needing more effort, longer stopping distance
  • Check engine lamp via the brake module request (P25A2)

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–3,500
Time0.5–4 h

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

Parts involved

booster motor b pos sensorbrake system control module

Related codes

C058AC058BC058CC058DC05B0P25A2

References: gsi.ext.gm.com, static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.