Diagnostic trouble code (DTC) information

Condition 

Fig 1: Identifying Brake Control Module & Active Yaw Control Sensor

Courtesy of VOLVO CARS OF NORTH AMERICA.

The yaw rate sensor, lateral accelerometer, accelerometer (only AWD) and angle of lean sensor (only RSC) are integrated in the active yaw control sensor. This in turn is connected to the brake control module (BCM) via its own Control area network (CAN) cable. The sensors transmit information to the brake control module (BCM) indicating the size of the yaw angle, the lateral acceleration of the car, the forward acceleration and the car's lateral angle of lean.

Diagnostic trouble code (DTC) BCM-0121, BCM-0125, BCM-0127 or BCM-0129 is stored, depending on the sensor, if the control module registers that the signal from any of the sensors is outside its permitted range.

• BCM-0121: Yaw rate sensor
• BCM-0125: Lateral acceleration sensor
• BCM-0127: Tilt angle sensor
• BCM-0129: Accelerometer.

Substitute Value 

• Traction control is blocked
• Stability control is blocked
• Active yaw control is blocked
• RSC is blocked (cars equipped with RSC only).

HINT: For information about abbreviations, see  Brake system, abbreviations  . 

Possible Source 

• Interference or noise on the wiring has disrupted the active yaw control sensor calculations
• The power supply to the active yaw control sensor is too low
• Incorrect wheel alignment
• Internal fault in the active yaw control sensor.

Fault symptom[s] 

• The anti-spin warning lamp is lit (up to and including 2002 model year)
• General yellow warning lamp lit (from model year 2003)
• Anti-spin does not function
• The stability control system does not function
• The traction control system does not function.