Steering Column Lock Module (SCL)

Fig 1: Identifying Steering Column Lock Module (SCL)

Courtesy of VOLVO CARS CORPORATION

The steering column lock module (SCL) (4/102) checks the function of the steering column lock. The control module is underneath the steering column inside the passenger compartment. The Steering column lock module (SCL) is connected in series to the Central electronic module (CEM) for communication and is directly connected to the Central electronic module (CEM) for power. The power supply is controlled by the Driver information module (DIM) via an internal relay in the Central electronic module (CEM). The central electronic module (CEM) transmits commands to the steering column lock module (SCL) when the steering lock needs to be locked or unlocked. The communication between the steering column lock module (SCL) and the central electronic module (CEM) is encrypted. Codes for the immobilizer function must be downloaded before the steering column lock module (SCL) can work in the vehicle. This takes place when downloading software.

The steering column lock module (SCL) consists of: 

• an electric motor
• a spring bolt
• a communication circuit
• a switch.

The steering column lock module (SCL) locks the steering wheel using the spring bolt. The spring bolt is moved back and forth by the electrical motor. The position of the spring bolt is indicated by the contact breaker in the steering column lock. The steering column lock module (SCL) transmits information at regular intervals about the position of the spring bolt to the central electronic module (CEM). A diagnostic trouble code (DTC) is stored in the central electronic module (CEM) if the spring bolt cannot be unlocked or its position cannot be determined. A message will also be shown in the display on the driver information module (DIM).

HINT: If the steering wheel is loaded when trying to unlock the steering column lock, the motor for the lock may be unable to unlock it (too much pressure on the spring bolt). An error message will be shown in the display on the driver information module (DIM) if this is the case. If this should happen, move the steering wheel slightly to reduce the pressure on the spring bolt, before a new start attempt. 

The steering column lock module (SCL) is powered by the central electronic module (CEM) and grounded in the body.