P0651 CHEVROLET 5 Volt Sensor Reference 2 Circuit

Possible causes
– Faulty Engine Control Module (ECM)
– ECM harness is open or shorted
– ECM circuit poor electrical connection
– Shorted sensor on 5 volt circuit
When is the obd code mean?
The Engine Control Module (ECM) has detected the sensor 5 volt reference circuit voltage is higher or lower than expected
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)