P0684 Buick Glow Plug Control Module- Implausible Signal
Possible causes
– Faulty Glow Plug Control Module (GPCM)
– GPCM harness is open or shorted
– GPCM circuit poor electrical connection
– Faulty Engine Control Module (ECM)
– GPCM harness is open or shorted
– GPCM circuit poor electrical connection
– Faulty Engine Control Module (ECM)
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
– Lack/Loss of Power
– The engine may be harder to start
– Engine hesitation
– Lack/Loss of Power
– The engine may be harder to start
– Engine hesitation
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