P0642 Buick Sensor Voltage Circuit A Low Voltage

P0643 Buick Sensor Reference Voltage A Circuit High

Possible causes
– Faulty Engine Control Module (ECM)
– ECM harness is open or shorted
– ECM circuit poor electrical connection
– Shorted sensor on 5 volt circuit
What about the obd code?
The Engine Control Module (ECM) has detected the sensor 5 volt reference circuit voltage is higher than expected
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
Buick Vehicle:Buick Regal – ?Buick Riviera – ?Buick LaCrosse – ?David Dunbar Buick – Buick Century – Buick LaCrosse – Buick LeSabre – Buick Lucerne – Buick Park Avenue – Buick Regal – Buick Verano – Buick Enclave – Buick Encore – Buick Rainier – Buick Rendezvous – Buick Terraza – Buick Riviera