P0674
Not individually documented
P0674 is a standardised code, but it is not one of the codes with a single agreed description. Rather than guess at a meaning, this page gives what its structure genuinely tells you and what we see when it turns up in real work.
What the code tells you on its own
- System
- Powertrain
- Functional group
- Glow plugs and preheat
- Subsystem
- Computer output circuit and ECU
- Failure type byte, when the tool sends one
- 00 (No sub-type information)
Engine, fuel, air, ignition, emissions and transmission. The overwhelming majority of what workshops bring to the AI.
Scan tools report the same fault as P0674 and as P0674xx, where xx is a sub-type. They are one fault, and whether the sub-type appears at all depends on the tool and the protocol rather than on the car.
What we see when P0674 turns up
Measured across the diagnostics run through Wrenchlane, not taken from a reference table. Figures as of 2026-10-06.
- Diagnostics
- 2
- Separate workshops
- 2
- Arrived code only
- 0%
- Most common marque
- Peugeot
September 2026
Not one shop meeting it repeatedly
No symptom description entered at all
Where we have seen it most
These are counts from our own work, not a claim about how common the fault is across all vehicles. They describe what independent workshops brought to us, which is a narrower and more specific thing.
Run P0674 against the car in front of you
Enter the code and the symptoms and get ranked probable causes for that specific vehicle, with the checks in the order worth doing them. Free account, no card.
Start freeOther glow plugs and preheat codes
- P0685 ECM/PCM power relay control circuit open
- P0671 Cylinder 1 glow plug circuit
- P0380 Glow plug or heater circuit A
- P0675 Cylinder 5 glow plug circuit
- P0684 Glow plug control module to PCM communication circuit range/performance
- P0672 Cylinder 2 glow plug circuit
- P0683 Glow plug control module to PCM communication circuit
- P0673 Not individually documented
FAQ
Frequently asked questions
How do I run a diagnosis?
Select the vehicle on Start, click the Diagnostic card and choose New diagnostic. Fill in the description, the error codes and the mileage, then click Analyze.
Learn more: Diagnostic (vehicle-first start), Diagnostic form: description, error codes and mileage
Do I have to type the codes from my scan tool?
No. Click the camera button next to Error codes and take or choose a photo (JPEG or PNG) of the scan tool's screen; WrenchLane reads the codes and their descriptions into the form. You can also speak them with the microphone.
Learn more: OBD reader photo scan (fault codes from a photo), Voice input for the problem description
Are the public fault code pages built from my diagnostics?
They are built from anonymised, aggregated diagnostics run in WrenchLane; no workshop, customer or vehicle can be identified. Each fault code page shows how often the code was seen across those diagnostics and in how many separate workshops.
Learn more: Fault code pages on wrenchlane.com (fault-code cluster)