The engine control module monitors current draw to ensure glow plugs function correctly. An incorrect code triggers when cylinder 1 draws too little or too much current. Low current draw means the plug is failing to heat up. High current draw indicates a short circuit. This mismatch often happens when installing the wrong type of glow plug. Mixing 5-volt and 12-volt plugs, or ceramic and metal plugs, will trigger this code.
Mechanic Glossary
1 Glow Plug Incorrect
A diagnostic trouble code indicating that the current draw or feedback signal from the cylinder 1 glow plug does not match factory specifications.
Frequently Asked Questions
The engine computer detected that the electric current draw from cylinder 1 glow plug is outside the normal, expected range.
Yes. Installing a glow plug with different resistance specs or voltage requirements than the factory design will trigger this fault.
Yes. The engine will run fine once warm. However, cold starts will remain rough, and you may fail emissions inspections.