What it means
The cylinder 12 glow plug control circuit voltage is above the expected range. The cause may be the plug, its wiring or connections, or the control circuit.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The engine controller monitors the cylinder 12 glow plug control circuit while diesel preheating is commanded. P06E3 sets when the circuit voltage exceeds the expected range, which can point to an open cylinder 12 plug or wire, a poor connection, or a wire touching a power supply.
Common causes
Most likely first.
- Open in plug or wiring
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Glow plug warning light on (often orange coil symbol)
- Hard cold start or no start in cold weather
- White smoke from exhaust during warm-up
How to diagnose it
- Record freeze-frame data and check whether any other glow plug circuit codes help distinguish a cylinder 12 fault from a broader supply problem.
- Locate cylinder 12 using the vehicle's cylinder identification information and inspect its lead for breaks, disconnection, pinching, or contact with a powered wire.
- Check the cylinder 12 connector for corrosion, loose terminals, and pins that have backed out.
- Test for an open in the cylinder 12 control circuit and check for an unintended connection to battery positive using the manufacturer's procedure.
- If the wiring is sound, test the cylinder 12 glow plug and its control output against the manufacturer's specification.
Common fixes
- Reconnect and secure the cylinder 12 glow plug connector.
- Repair an open or damaged section of the cylinder 12 control wire.
- Repair wiring pinched against a power supply.
- Replace the cylinder 12 glow plug or repair its control circuit if testing confirms the cause.
Can I keep driving?
Cold starting may become difficult, with white smoke during warm-up, even if the engine runs normally once warm. Have the cylinder 12 circuit checked before depending on the vehicle in cold weather.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.