Chassis, generic

C0574 Brake Pressure Sensor C Circuit Range/Performance

Check engine lightOn
EmissionsNot relevant
Drive cycleRequired
Limp modePossible

Here the sensor C signal is electrically within limits but does not make sense. GM's 2016–2019 hybrid brake modules learn the zero point while the pedal is released and set C0574 if the offset exceeds ±1,500 kPa; to confirm a repair the car is driven at about 37 mph for 5 s without braking. A 2019 EBCM compares its two secondary circuit pressure signals with each other and with pedal travel (difference above 5 bar), checks each learned offset (above 10 bar) and catches erratic readings within 80 ms. The 2023 and 2025 tables allow an offset of 12 bar. All are Type A with MIL. A Lucas/ZF patent shows why several sensors are needed: only a comparison of three or more at a shared pressure tells which one has drifted.

Likely causes

Pressure sensor zero point drifted with age or temperature
Residual pressure while learning, e.g. dragging pedal or sticking valve
Poor sensor ground shifting the signal level
Sensor values not relearned after replacing the brake module

Symptoms

  • Check engine light and ABS or stability lamp (GM)
  • Uneven or changed braking feel when regeneration blends in
  • Code returns after clearing once the car has been driven

Repair estimate

DifficultyHardWorkshop job
Parts and labour€60–2,500
Time0.5–4 h

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

Parts involved

brake pressure sensor cbrake control module

Related codes

C0571C0572C0573C059CC053D

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