Controller Area Network (CAN) Description

The EBCM communicates with the yaw rate sensor and the steering wheel angle sensor exclusively, when equipped. This serial data system does not communicate with the scan tool however; there are loss of communication DTCs for this system which set in the EBCM. The yaw rate sensor and the steering wheel angle sensors are in effect modules, exchanging essential information with the EBCM. For more information about these sensors refer to ABS Description and Operation . The CAN system functions in a manner similar to high speed GMLAN. A key difference is circuit voltage. In this CAN application the EBCM places 3 volts on the CAN bus high serial data circuit and 2 volts on the CAN bus low serial data circuit. The Yaw rate and steering angle sensors, when either are present, drive both circuits to a 2.5 voltage level. Communications occurs when the circuits are then switched to 3 volts and 2 volts respectively. Expected values would be 3 volts and 2 volts when using a digital multimeter to test these circuits with the sensors disconnected and approximately 2.5 volts on both with either sensor connected.