Chassis, generic

C0240 Brake Pressure Sensor

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

C0240 cannot be verified publicly: it is missing from the accessible J2012 lists, from the NHTSA bulletin index, from GM's PIP5094 keyword list and from the Saab and Mitsubishi indexes. Only the part in the title can be described. In a modern brake control unit a pressure sensor reports how hard the driver presses; on the TRW EBC450 of the 2011 Saab 9-5 it is built into the valve block. The module feeds it 5 V and expects about 0 V with the pedal released and more than 1 V when braking. A broken supply or signal line, or a reading that does not fit the deceleration or brake switch, disables ABS, traction and stability control; GM files that fault under C0131. Brake assist and stability control use this signal to judge braking demand.

Likely causes

Open or shorted 5 V supply or signal wire to the pressure sensor
Faulty pressure sensor inside the hydraulic unit
Sensor offset not calibrated after module or valve block replacement

Symptoms

  • ABS, traction and stability warning lamps on
  • Brake assist and stability control unavailable

Repair estimate

DifficultyHardWorkshop job
Parts and labour€50–1,500
Time0.5–3 h

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

Parts involved

brake pressure sensorabs hydraulic unitabs control module

Related codes

C0131C0161C0110

References: saabwisonline.com, saabwisonline.com, bosch-mobility.com.