Chassis, generic

C063D Brake Pressure Sensor J Circuit/Open

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

A wire or contact of brake pressure sensor J is interrupted. No manufacturer ties C063D to a specific sensor. Continental's one-box brake patent names sensors for the master cylinder and for the pressure supply unit and mentions optional further ones for brake circuits or wheel brake circuits, so a J sensor could be among those. Bosch Motorsport's EBS illustrates per-channel fault flags: internal axle pressure, internal master cylinder pressure and the external caliper and master cylinder sensors each have their own bit. GM's 2019 EBCM does not separate an open from a short to voltage at all; both end up as open or shorted high above 95.24 % of supply. So check plug, terminals and harness first, even if the stored code says high instead of open.

Likely causes

Spread or corroded terminal in the sensor connector
Conductor interrupted between sensor and control unit
Open circuit inside sensor J

Symptoms

  • Brake system or ESC warning lamp on
  • Pressure-controlled brake functions switched off

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€40–1,500
Time0.5–3 h

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

Parts involved

brake pressure sensor jsensor wiring

Related codes

C063EC063FC0640C0639C0641

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