Possible causes – Idle Air Control Valve (IACV)/Auxiliary Air Control (AAC) Valve harness is open or shorted– Idle Air Control Valve (IACV)/Auxiliary Air Control (AAC) Valve circuit poor electrical connection– Faulty Idle Air Control Valve (IACV)/Auxiliary Air Control (AAC) Valve When is the obd code mean? The P0511 code is set when the Idle Air…