Cylinder 8 Glow Plug Control Circuit Low
This code means the PCM/ECM has detected a low-voltage control circuit condition affecting cylinder 8 glow plug. Because combustion on the affected cylinder or circuit is disrupted, drivers may notice rough running, misfires, hard starts, or reduced power.
What You Might Notice
- Check Engine Light illuminated
- Hard cold starting
- Long cranking in cold weather
- Rough idle after start-up
- White smoke on cold start
Most Common Causes
- 1
Failed glow plug
- 2
Faulty glow plug control module or relay
- 3
Open or high-resistance glow plug wiring
- 4
Low battery voltage
- 5
PCM/ECM fault
How to Diagnose It
- 1
Check Failed glow plug — Inspect for signs of failure and test before replacing.
- 2
Check Faulty glow plug control module or relay — Inspect for signs of failure and test before replacing.
- 3
Check Open or high-resistance glow plug wiring — Inspect for signs of failure and test before replacing.
- 4
Check Low battery voltage — Inspect for signs of failure and test before replacing.
- 5
Check PCM/ECM fault — Inspect for signs of failure and test before replacing.
How to Fix It
- 1
Test the affected coil, glow plug, or ignition-related component
- 2
Inspect spark plugs and basic engine condition
- 3
Repair damaged wiring, grounds, or connector pins
- 4
Replace the failed ignition-related part
- 5
Clear the code and confirm the symptom is gone
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