P0676
Cylinder 6 Glow Plug Circuit/Open.
- Generic
- Powertrain
- Generic code
- Low severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 6
- AreaComputer and output circuits
- 76
- FaultThe specific fault in that area
What it means
P0676 means the engine control unit has detected an open circuit or fault in the glow plug circuit for cylinder 6. The glow plug control module or ECU monitors current or voltage in each glow plug circuit and found it outside the expected range, usually no current flow. It only applies to diesel engines, and the way cylinder 6 is wired and diagnosed depends on the model and engine.
Symptoms
- Glow plug warning lamp or engine management light on
- Harder starting in cold weather
- Rough running or white smoke on a cold start
- Slightly higher emissions or increased diesel knock until warmed up
- No noticeable change when the engine is warm
Possible causes
- Failed glow plug on cylinder 6 (open-circuit heating element)likely
- Corroded, loose or damaged glow plug connector or terminal on cylinder 6likely
- Damaged wiring between the glow plug control module and cylinder 6 glow plug (open circuit, chafing, broken wire)possible
- Poor earth connection or low supply voltage to the glow plug system, such as a weak battery or corroded power feedpossible
- Blown fuse or failed relay in the glow plug supplypossible
- Faulty glow plug control module or output driver for cylinder 6rare
How to diagnose
- Read all stored codes and freeze frame data, and note whether other glow plug cylinder codes are also set, which would point to a common supply, fuse or module fault.
- Check battery condition and charging voltage, as low voltage can upset glow plug circuit monitoring.
- Visually inspect the cylinder 6 glow plug connector, terminal and wiring for corrosion, heat damage, chafing or looseness.
- Check the glow plug fuse and relay or supply feed as described in the model's wiring information.
- Measure the cylinder 6 glow plug resistance or current draw with the plug disconnected or in circuit, following the manufacturer's procedure and specification, and compare it with the other cylinders.
- Test the wiring for continuity and for a good supply and earth between the control module connector and the glow plug.
- If the plug and wiring are sound, check the control module output using live data or an output test where the vehicle supports it, and confirm against the manufacturer's diagnostic procedure.
How to fix
- Replace the failed cylinder 6 glow plug, taking care with torque and removal, as seized or brittle plugs can snap in the head.
- Clean or replace the damaged glow plug connector or terminal.
- Repair or replace the faulty wiring section between the module and the glow plug.
- Restore a good supply, earth and battery condition, and replace any failed fuse or relay once the cause of failure is found.
- Replace the glow plug control module only after the plugs, wiring and supply have been proven good, and code or adapt it if the vehicle requires.
Can I keep driving?
Low severity
The car can normally be driven, but cold starting may be harder and emissions may be higher until it is repaired. Book it in soon, especially before cold weather, and avoid repeated long cranking attempts.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.