Cylinder 6 Glow Plug Circuit Low
The glow plug circuit for cylinder 6 has a low voltage reading.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
Inside the engine, there's a glow plug for cylinder 6 that helps to heat up the combustion chamber during cold starts. If it's not getting enough voltage (less than about 9 volts), it can't heat properly, leading to hard starts and rough running.
What the computer is actually seeing
The engine control module (ECM) monitors the voltage on the glow plug circuit. When it sees less than 9 volts when the glow plug should be energized, it sets this code.
What a healthy reading looks like
Glow plugs should see around 12 volts when activated; a functioning glow plug should measure low resistance (typically between 0.5 to 1.5 ohms).
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check the engine harness for damaged wires or connectors at the glow plug.
- 2 - If damaged, repair the wiring or connectors as needed. If not, proceed to step 2.
- 32. Measure the voltage at the glow plug connector with the ignition on (engine off).
- 4 - If voltage is below 12 volts, check for power at the glow plug relay or fuses. If good, replace the glow plug.
- 5 - If voltage is normal, proceed to step 3.
- 63. Test the glow plug resistance with a multimeter (disconnect the wire first).
- 7 - If resistance is out of range (not between 0.5 - 1.5 ohms), replace the glow plug. If good, check the ECM operation.
Common causes
- Faulty glow plug
- Open circuit or short in the wiring
- Bad connector or corrosion
- Faulty ECM
Typical repair cost
$$ - $$$
Related codes
Frequently asked questions
Is it safe to drive with this code present?
Yes, but expect poor cold starts and increased emissions until repaired.
Will the code return after clearing?
Yes, if the underlying issue isn't fixed, the code will likely come back.
Why does this code only show for cylinder 6?
Each cylinder has its own glow plug; this code specifically indicates a problem with cylinder 6's glow plug circuit.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →