P1918 Buick Transmission Range Display Circuit Malfunction

P2000 Buick Oxides of Nitrogen Trap Efficiency Below Threshold Bank 1

Possible causes
– Sensor or solenoid faulty
– Connector terminal contact is damaged or corroded
– Wire harness – Check harness for correct voltage, open, short to ground or short to voltage
– Update control unit software – Check for the latest control unit update
– Powertrain or Engine Control Module faulty
– Catalytic converter damage
– Catalytic converter improper operation

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