Chassis, generic

C063E Brake Pressure Sensor J Circuit High

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

C063E: sensor J sends more voltage than its range allows. GM's 2016 hybrid brake controller shows the method on a wheel pressure sensor: if the signal line exceeds 3.3 V and so no longer differs from the supply, a short to supply is stored after 0.1 s with the ignition on, rated Type A. Denso's patent explains the second route: with a pull-down at the input, an open sensor ground forms a divider that pushes the line beyond 4.7 V. No public source says which part is sensor J; brake-by-wire units such as Bosch Motorsport's EBS already measure axle, driver, caliper and master cylinder pressure separately. A falsely high value would look like braking that is not happening, so the module discards the signal and limits its functions.

Likely causes

Signal line shorted to the sensor supply
Sensor ground interrupted, output lifted through the input divider
Sensor J electronics failed with output stuck high

Symptoms

  • Brake or ESC warning lamp on
  • Live data shows brake pressure although no one is braking

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–1,600
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

C063DC063FC0640C063AC0576

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