OBD
P06C4
Cylinder 12 Glow Plug Circuit Range/Performance
What it means
P06C4 means Cylinder 12 Glow Plug Circuit Range/Performance.
Check these first
- A weak glow plug in cylinder 12
- A corroded cylinder 12 connector
- An intermittent glow plug feed
- A failing glow plug module
- Poor diesel fuel quality
What to do next
- Watch cylinder 12 glow plug current
- Inspect the connector and wiring
- Test the glow plug
- Check the glow plug module
- Replace the glow plug or module
- Clear the code and retest
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Updated
Generic SAE J2012 definition. Last updated 2026-10-10.