OBD-II Symbol Description Notice
WARNING: This page is about a different car, the 2006 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
The OBD-II symbol is used on the circuit diagrams in order to alert the technician that the circuit is essential for proper OBD-II emission control circuit operation. Any circuit which fails and causes the malfunction indicator lamp (MIL) to turn ON, or causes emissions-related component damage, is identified as an OBD-II circuit.