ACTIVATING COMPONENTS
This function can be used to activate components to check that they are working.
New software can be downloaded to the Central electronic module (CEM).
When ordering software the vehicles hardware and software are compared with Volvo's central database. If the comparison is correct the software is downloaded to the control module.
If the comparison between the car and Volvo's central database does not correspond, then the database is updated with the vehicles configuration. When this is complete the software is downloaded.
The position sensor for headlamp range adjustment must be calibrated when the control module is replaced. Calibration must also be carried out when replacing the position sensor for headlamp range adjustment. This is carried out using the diagnostic tool via the vehicle communication input.
Scheme 495
For vehicles without Four-C (Continuously Controlled Chassis Concept), the position sensors (7/119, 7/121) for rear wheel suspension and front wheel suspension send information to the Central electronic module (CEM) (4/56) on vehicle angle as regards load conditions, acceleration and braking.
For vehicles with Four-C (Continuously Controlled Chassis Concept), the Suspension module (SUM) (4/84) transmits information to the Central electronic module (CEM) about vehicle angle as regards load conditions, acceleration and braking.
The Central electronic module (CEM) uses the information from the position sensors or suspension module (SUM) to calculate the actual angle for headlamp levelling.
The Central electronic module (CEM) transmits information on the actual angle to the left headlamp control unit (LHCU) and right headlamp control unit (RHCU) via serial communication. The actuator motors are then controlled by the left headlamp control unit (LHCU) or right headlamp control unit (RHCU), respectively, via an analogue signal.
Scheme 496
Active headlamps are an intelligent headlamps system that optimizes lighting of the road surface at night by expanding the light beam. The motorized headlamps are controlled by the Central electronic module (CEM), which retrieves signals from the CAN network and, in some cases, from directly connected sensors.
For the active headlamp function to be activated the Central electronic module (CEM) (4/56) requires information about the vehicle speed, gear and steering wheel angle.
The Central electronic module (CEM) receives information from the following control modules
- Brake control module (BCM) (4/16) information about vehicle speed
- Transmission Control Module (TCM) (4/28) information about the current gear (automatic gearbox)
- Steering wheel angle sensor module (SAS) (3/130) information about the steering wheel angle
- The Central electronic module (CEM) also used internal signals: information about the brake lamp switch (3/10) (manual gearbox) information from the twilight sensor (7/12)
The active headlamp function is only enabled if the following conditions are met
- The vehicle must be in motion, that is, travel at a speed faster than 4 km/h.
- Reverse gear must not be engaged.
- No daylight light conditions.
Also, the function active headlamp must be activated. The function in active headlamp is deactivated/activated via the menu system in Infotainment control module (ICM) (3/281).
When the function is active, the Central electronic module (CEM) receives continual information on vehicle speed and steering angle. Vehicle speed is obtained from the brake control module (BCM) while steering angle information comes from the steering wheel angle sensor module (SAS) (3/130). This information enables the Central electronic module (CEM) to calculate the current turn-out of the light beam.