Chassis, generic

C059B Brake Pressure Sensor B Missing Calibration

Check engine lightOn
EmissionsNot relevant
Drive cycleRequired
Limp modePossible

The brake module cannot confirm that pressure sensor B has been calibrated and that its sensitivity is right. GM uses C059B in the brake controller of its 2016 and 2019 hybrid tables for the rear-left wheel pressure sensor: during a test pulse the sensor response must stay between 90 % and 110 %, checked only after at least one completed offset learn, with low master cylinder pressure and no ABS, traction or stability intervention. Type A, MIL after one trip; to confirm a fix, drive above about 6 mph for a minute without braking. In those same tables the rear-left sensor's circuit faults use C0575–C0578. A Bosch patent likewise treats a failed test pulse as a sensitivity fault with ABS and ESC lamps on. Ford checks sensor data by checksum and ID, but only for sensor A (C0560).

Likely causes

Calibration or offset learn not completed after module or hydraulic unit replacement
Pressure sensor responding outside the allowed test-pulse window
Brake control module storing or evaluating calibration data incorrectly

Symptoms

  • ABS and stability control warning lamps on, MIL possible
  • Regenerative braking blending or ESC functions restricted

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–1,500
Time0.5–3 h

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

Parts involved

brake pressure sensor bbrake control module

Related codes

C0560C059CC059DC059EC0541C0578

References: gsi.ext.gm.com, gsi.ext.gm.com, patents.google.com, fordservicecontent.com.