OBD
P06B9
Cylinder 1 Glow Plug Circuit Range/Performance
What it means
P06B9 means Cylinder 1 Glow Plug Circuit Range/Performance.
Check these first
- A weak glow plug in cylinder 1
- A corroded cylinder 1 glow plug connector
- An intermittent glow plug feed
- A failing glow plug relay
- A weak battery
What to do next
- Watch cylinder 1 glow plug current on a scan tool
- Inspect the connector and feed wire
- Test the glow plug resistance
- Check the relay and battery
- Replace the glow plug or relay
- Clear the code and retest
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Updated
Generic SAE J2012 definition. Last updated 2026-10-10.