P0671 GMC -

Question

how to fix code P0671 on 2010 Gmc duramax. Have continuity for #1 glow plug and circuit back to controller.

Answer 1

P0671 Cylinder # 1 glow plug control circuit

The connection at the glow plug has to be secure, Poor or loose connection on the glow plug will cause this code., There only 2 possible failed area , the glow plug controller , or  the glow plug itself, P0671 has always been set due to loose connection.