P0039 Buick Turbocharger Bypass Valve Control Circuit Range/Performance

P0040 Buick 1/1 And 2/1 O2 Sensor Harness Connectors Reversed

Possible causes
– 1/1 And 2/1 O2 sensors harness is open or shorted
– 1/1 And 2/1 O2 sensors circuit connectors (wrong connection)
– Faulty Powertrain Control Module (PCM)
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0040 Buick Description

At ignition on the Powertrain Control Module (PCM) checks the voltage on the ground side of the O2 sensor harness connector. If voltage is higher than two volts the P0040 Buick code will set.

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