The engine computer verifies that all glow plugs draw similar current during cold starts. If the current draw on cylinder 3 deviates from the others, the computer logs this fault code. This occurs when the plug's internal coil degrades or you install the wrong replacement plug. Always use matching brand and voltage ratings across all cylinders to avoid current feedback differences.
Mechanic Glossary
3 Glow Plug Incorrect
A fault indicating that current consumption or resistance values measured from cylinder 3 glow plug mismatch expected parameters.
Frequently Asked Questions
A degraded glow plug element changing its resistance, or installing an aftermarket plug that does not match the factory voltage specifications.
You can, but it is not recommended. Old plugs have higher resistance than new ones, which can trigger an incorrect current draw fault code.
Cold starts might be slightly rough or produce a small puff of smoke, but once running, the engine will perform normally.