P0684 Code: Meaning, Causes, and Symptoms | OBD2 Codes

P0684 – Glow Plug Control Module to ECM Communication Circuit Range/Performance


P0684: DIY Repairing Video Tutorial


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P0684 Possible Symptoms

  Engine Light ON (or Service Engine Soon Warning Light),Lack/Loss of Power,The engine may be harder to start,Engine hesitation  

P0684 Possible Causes

  Faulty Glow Plug Control Module (GPCM),GPCM harness is open or shorted,GPCM circuit poor electrical connection,Faulty Engine Control Module (ECM)  

P0684 Description

  The Engine Control Module (ECM) monitors the Glow Plug Control Module (GPCM). The ECM sets the OBDII code when can not communicate with the Glow Plug Control Module.