P067F
Cylinder 6 Glow Plug Control Circuit High.
- Generic
- Powertrain
- Generic code
- Medium severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 6
- AreaComputer and output circuits
- 7F
- FaultThe specific fault in that area
What it means
P067F means the engine control unit has detected a high voltage or short to voltage fault in the glow plug control circuit for cylinder 6. The control unit monitors the circuit feedback and sees a voltage or current state that does not match what it commanded. Exact circuit layout and how the plugs are driven (individual driver or shared module) depend on the model and engine.
Symptoms
- Engine management warning light or glow plug warning light on
- Hard starting or extended cranking when cold
- White smoke and rough running on a cold start
- Noticeable misfire or uneven idle until the engine warms up
- Increased diesel knock on cold start
- Glow plug system not operating on cylinder 6 with no other obvious symptoms in warm weather
Possible causes
- Faulty cylinder 6 glow plug (internal short or failed element)likely
- Damaged, chafed or corroded wiring between the glow plug control module or ECU and the cylinder 6 pluglikely
- Poor connections or water ingress at the glow plug connector or control module plugpossible
- Fault in the glow plug control module or output driver for cylinder 6possible
- Wiring short to a voltage supply within the loompossible
- Fault within the engine control unit itselfrare
How to diagnose
- Read all stored codes and freeze frame data, noting engine temperature, battery voltage and whether other glow plug codes are present
- Check battery condition and charging voltage, as low or unstable voltage can upset glow plug diagnostics
- Visually inspect the glow plug wiring, connector at cylinder 6 and the control module plug for damage, heat marking, corrosion or moisture
- Check the cylinder 6 glow plug resistance and compare it with the other plugs and the manufacturer specification
- Check the wiring from the control module to cylinder 6 for a short to voltage and for continuity, following the model wiring diagram
- Using live data or an output test where supported, command the glow plugs and monitor cylinder 6 response and current
- Check the module supply voltage, earths and power feed against the manufacturer procedure
- Clear the code and road test, then recheck to confirm whether the fault returns
How to fix
- Replace the cylinder 6 glow plug if it is shorted or out of specification, and consider the condition of the others if they are of similar age
- Repair or replace damaged wiring or the affected section of loom
- Clean, dry or replace corroded or damaged connectors and terminals
- Replace the glow plug control module if it is confirmed faulty, following any coding or adaptation steps required for the model
- Repair any wiring short to voltage and recheck the circuit before refitting components
Can I keep driving?
Medium severity
The car can usually be driven for a short time, but cold starting and emissions may suffer and the fault may worsen or affect other glow plug circuits. Have it checked soon, especially before cold weather.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.