On Board Diagnostics II (OBDII) Symbol

On-Board Diagnostics II (OBDII) Symbol:

The On-Board Diagnostics II (OBDII) symbol is used on circuit diagrams to alert the technician that the circuit is essential for OBDII emission control circuit operation. Any circuit which, if it fails, causes the SERVICE ENGINE SOON indicator to turn on, is identified as an OBDII circuit.