P0671–P0682 Cylinder 1 Glow Plug Circuit/Open
The circuit is broken somewhere - a cut wire, a corroded pin or an unplugged connector means the signal never arrives.
Can you drive it? Glow plugs only help a cold diesel start. Once the engine is running it normally drives as usual, but cold starts get harder and smokier until it is fixed.
Which code is which
Same fault, different cylinder or bank — diagnosed the same way. Several set together usually means one shared cause.
| Code | Definition | Severity |
|---|---|---|
P0671 | Cylinder 1 Glow Plug Circuit/Open | Investigate soon |
P0672 | Cylinder 2 Glow Plug Circuit/Open | Investigate soon |
P0673 | Cylinder 3 Glow Plug Circuit/Open | Investigate soon |
P0674 | Cylinder 4 Glow Plug Circuit/Open | Investigate soon |
P0675 | Cylinder 5 Glow Plug Circuit/Open | Investigate soon |
P0676 | Cylinder 6 Glow Plug Circuit/Open | Investigate soon |
P0677 | Cylinder 7 Glow Plug Circuit/Open | Investigate soon |
P0678 | Cylinder 8 Glow Plug Circuit/Open | Investigate soon |
P0679 | Cylinder 9 Glow Plug Circuit/Open | Investigate soon |
P0680 | Cylinder 10 Glow Plug Circuit/Open | Investigate soon |
P0681 | Cylinder 11 Glow Plug Circuit/Open | Investigate soon |
P0682 | Cylinder 12 Glow Plug Circuit/Open | Investigate soon |
The definition
P0671: Cylinder 1 Glow Plug Circuit/Open.
P0671 is a powertrain code (the engine or gearbox), defined by the SAE standard - it means the same thing on any make of car, and any generic OBD-II reader will decode it.
What to check first
Cheapest and fastest checks first:
- Check the connector is fully seated and the locking tab is engaged. A half-seated plug is the single most common cause of an open circuit.
- Back-probe the pins and check continuity from the part back to the module connector.
- Inspect for a pushed-back or corroded terminal - the wire looks fine but the pin has backed out of the housing.
Reading the code is the easy part
A code names the circuit that complained. What tells you why is watching the sensor behind it while the engine runs — and that is where a code reader stops and a diagnostic tool starts.
VAGPULSE reads your engine ECU's fault codes and the live measuring blocks behind them, and clears the codes once you have fixed the fault. On the engine it also does what a generic OBD reader cannot on a VAG: coding, adaptations, and Stage 1–3 flashing on Bosch ME7 petrol ECUs, with a backup saved every time it reads your ECU.
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Common questions
What does P0671 mean?
P0671 means Cylinder 1 Glow Plug Circuit/Open. The circuit is broken somewhere - a cut wire, a corroded pin or an unplugged connector means the signal never arrives.
Can I drive with P0671?
Glow plugs only help a cold diesel start. Once the engine is running it normally drives as usual, but cold starts get harder and smokier until it is fixed.