P068E
Cylinder 8 Glow Plug Control Circuit Low
Glow plug / diesel preheat
Generic OBD-II
Medium
What it means
P068E means the engine computer sees low voltage — a short to ground — in the control circuit for the cylinder 8 glow plug on a diesel engine. Glow plugs preheat the cylinders for starting, so the fault mostly affects cold-start quality, giving harder, rougher, smokier starts, rather than how the engine runs once it is warm.
Medium
Can I keep driving? Usually yes — the engine still runs, but cold starts may be harder and rougher until the cylinder 8 glow plug circuit is repaired.
Common symptoms
What you'll notice
- Hard starting in cold weather
- Glow plug or check-engine light on
- Rough running and white smoke on a cold start
- Reduced performance until the engine warms up
Common causes
Most likely first
- Cylinder 8 glow plug shorted internallyLikely
- Glow plug wiring shorted to ground or chafedCommon
- Corroded or loose connector pulling the circuit lowCommon
- Faulty glow plug control moduleLess often
How to diagnose & fix
Work through it in order
- Scan and confirm P068E, then read freeze-frame.
- Inspect the cylinder 8 glow plug wiring for shorts to ground or chafing.
- Measure the glow plug resistance; a shorted (very low) reading means a failed plug.
- Replace the glow plug or repair the shorted wiring.
- If the plug and wiring check out, test the glow plug control module.
FAQ
Quick answers
Is it safe to drive with P068E?+
Usually — the diesel runs on its other cylinders, but cold starts suffer. Repair it before cold weather.
Can I just clear P068E?+
It returns after the next glow-plug test unless the short is repaired.
Related codes
Often seen with P068E
Read & clear P068E yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX