Chassis, generic

C059F Brake Pressure Sensor E Circuit Low

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

The signal of brake pressure sensor E sits below its valid window. Analogue brake pressure sensors run on 5 V and report roughly 0.5–4.5 V; a Bosch trainer notes such a sensor shows under 1 V with the brake released. A Denso patent on vehicle pressure sensors reserves 0–0.3 V as an error band and explains that, with a pull-down resistor at the module, a broken supply or signal wire also drags the reading to 0 V, so an open circuit can appear as low here. Other causes are a short of the signal to ground or a failed sensor. No maker documents C059F publicly. GM's hybrid brake controller uses the same kind of check on its wheel pressure sensors: below 0.3 V lasting 100 ms, rated Type A. Sensor E is usually built into the hydraulic unit, so a sensor fault often means replacing that unit.

Likely causes

Signal wire of the sensor shorted to ground
Open 5 V supply or signal wire pulled low by the module input
Pressure sensor failed internally (often part of the hydraulic unit)

Symptoms

  • ABS/ESC warning lamp on
  • Stability control and pressure-based brake functions switched off

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–1,800
Time0.5–4 h

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

Parts involved

brake pressure sensor esensor wiring

Related codes

C05A0C05A1C05A2C059EC05C6C0575

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