Engine Control Module: Testing and Inspection

Downloading software and replacing the control module

Upon replacement of the engine control module (ECM), the hardware number of the control module is read out and sent to Volvo's central database. Software structure is based on vehicle configuration (for example, structure week and hardware number). The software is then sent down to VIDA and can be downloaded.
A vehicle identity check, a read off of the vehicles' new configuration for updating the Volvo central database and programming of codes are included in the download sequence. The procedure when updating software is identical except that the hardware number is not read but taken directly from the Volvo central database. For further information regarding downloading, see Design and Function, software download.
The engine control module (ECM) is included in the immobilizer system and a number of conditions must be met for the control module to approve a start.
Immobilizer code: During the start attempt, the central electronic module (CEM) sends out its immobilizer code. The engine control module (ECM) receives the code and compares it to the code programmed there. If the codes match, this condition is fulfilled.
Serial number: The serial number of the brake control module (BCM) is programmed in the engine control module (ECM). During the start attempt, the engine control module (ECM) queries the brake control module (BCM) for the serial number programmed there and compares it to the serial number programmed in the engine control module (ECM). If the serial numbers match, this condition is fulfilled.
Both conditions must be met to allow a start. When replacing the engine control module (ECM), both the immobilizer code and serial number are programmed in automatically when downloading software.