The engine computer tracks current draw across all twelve glow plugs. Incorrect code triggers when cylinder 12 glow plug draws abnormal current. If the heating element is worn or has a different internal resistance, this code displays. Always install a glow plug that matches the resistance specifications of the other eleven cylinders.
Mechanic Glossary
12 Glow Plug Incorrect
A fault code indicating the current draw from the cylinder 12 glow plug does not match factory standards.
Frequently Asked Questions
The engine computer detected that the electrical current flowing through cylinder 12 glow plug is incorrect.
Yes, but make sure the replacement plug has the exact same voltage and resistance specs as the other plugs.
One bad plug won't prevent a V12 from starting. It will start, but it will idle rough and puff smoke for a few seconds.