Component description for the SCR frame module control unit

B14.40-0092-05

Arrangement

A95 SCR chassis control module

The SCR chassis control module (A95) is located between the battery and the right side rail.

Task

The SCR chassis control module (A95) reads the analog signals of the interconnected sensors, to digital CAN (Controller Area Network) signals, and sends these to the engine control module (MR).

Besides, the chassis control module (A95) supplies feeding voltage to the available active sensors to catch the signals of the interconnected components of the control module (MR).

The SCR chassis control module (A95) reads the analog signals of the following sensors:

 Temperature sensorbefore the SCR catalytic converter (B115)

 Temperature sensorafter the SCR catalytic converter (B116)

 Combined AdBlue level and temperature sensor (B117)

 Combined SCR humidity and temperature sensor (B132)

The analog signals are converted in the chassis control module (A95) into digital CAN-Bus signals and transmitted as a cyclic status report to the engine control module (MR).

In the engine control module, the signals are processed and transmitted via the CAN-Bus to the chassis control module (A95) which, next, actuates the following components:

 SCR AdBlue pump (M25)

 Pressure limiting solenoid valve (33.01/Y128)

No data application is available in the chassis control module (A95). Also no elimination or storage of error data is carried out. This task belongs to the engine control module (MR) that receives all necessary information vie the CAN-Bus.

After turning off the ignition, the chassis control module (A95) continues operating, provided the engine control module (MR) signals are received.