Circuit/System Testing: Notes

NOTE:

Some devices with an internal terminating resistor have a loop in the harness that connects the internal terminating resistor to the serial data circuit. When wired this way, test these loop circuits for the appropriate failure mode short to voltage, short to ground or open/high resistance prior to replacing the device for each of the following tests. Each device may need to be disconnected to isolate a circuit fault. Use the schematics and connector end views to identify the following:

Object high speed GMLAN devices and terminating resistors the vehicle is equipped with
Device locations on the object high speed GMLAN serial data circuits
Each device's ground, B+, ignition and object high speed GMLAN serial data circuit terminals

NOTE: Circuit/System Verification must be performed before proceeding with Circuit/System Testing.