This bulletin applies to 2012 Volkswagen Passat Sedan models. The MIL may be on, with DTCs P0671, P0672, P0673 and/or P0674 stored in ECM fault memory.

P0671……….cylinder 1 glow plug circuit

P0672……….cylinder 2 glow plug circuit

P0673……….cylinder 3 glow plug circuit

P0674……….cylinder 4 glow plug circuit

An internal hardware issue of the glow plug relay may cause an over-voltage supply to the glow plug(s), damaging the heating element.

An improved glow plug relay design has been implemented in production and in replacement parts. Replace the affected glow plug(s), referring to Group 28 in ElsaWeb.