The engine computer monitors the current draw of cylinder 8. If the draw doesn't match the other cylinders, this code triggers. This occurs when the plug has degraded or the wrong replacement plug was installed. Check that the replacement matches the other glow plugs.
Mechanic Glossary
8 Glow Plug Incorrect
A fault indicating that current draw from the cylinder 8 glow plug is outside parameters.
Frequently Asked Questions
The engine computer detected that the electrical current draw of cylinder 8 glow plug is incorrect.
You likely installed a glow plug with the wrong voltage or resistance rating. Make sure it matches the factory specs.
Install the correct glow plug. The computer will clear the code once it detects the correct current draw.