VOLVO
BCM-C111802 - Brake servo disengage switch. General malfunction information. General signal error
System
Brake Control Module (BCM)
Volvo models this fault code applies to
Applies to the following models:
1 modelXC90 (2003–)
What does this fault code mean?
The brake control module (BCM) has received a signal from the pedal pressure sensor in the brake booster that it judges to be implausible, so it cannot determine with certainty whether the brake pedal is pressed. The code only applies to cars with DSTC. The stability systems and brake assistance are switched off for as long as the fault remains.
Possible causes
- Contact resistance or oxidation in connectors and joints
- Open circuit in the wiring, or wiring shorted to ground or supply voltage
- Damaged pedal pressure sensor
- Damaged brake control module
What you can do
- 1Check the plugs at the brake control module and at the pedal pressure sensor for poor contact and oxidation
- 2Have a workshop read the pedal pressure sensor status: it should be off with the pedal untouched and switch on when the pedal is pressed
- 3Check the wiring for breaks, chafing and short circuits to ground and supply voltage
- 4If the sensor gives a wrong value despite intact wiring, a workshop needs to replace the brake booster
- 5The brake system is safety-critical, so have a workshop carry out all work on the brake booster and the module
Symptoms you may notice4
- General warning lamp on
- Traction control does not work
- Stability function does not work
- Anti-skid function does not work
What the fault can affect2
- Traction control, stability control and dynamic stability control (AYC) are disabled
- Brake assistance (BA) is disabled
General guidance for car owners. Diagnosis on the car can point to a different cause.