P3401–P3489 Cylinder 1 Deactivation/Intake Valve Control 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? This class of fault can cause real mechanical damage if you keep driving on it. A persistent misfire also destroys the catalytic converter, which is the expensive part.
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 |
|---|---|---|
P3401 | Cylinder 1 Deactivation/Intake Valve Control Circuit/Open | Do not keep driving |
P3409 | Cylinder 2 Deactivation/Intake Valve Control Circuit/Open | Do not keep driving |
P3417 | Cylinder 3 Deactivation/Intake Valve Control Circuit/Open | Do not keep driving |
P3425 | Cylinder 4 Deactivation/Intake Valve Control Circuit/Open | Do not keep driving |
P3433 | Cylinder 5 Deactivation/Intake Valve Control Circuit/Open | Do not keep driving |
P3441 | Cylinder 6 Deactivation/Intake Valve Control Circuit/Open | Do not keep driving |
P3449 | Cylinder 7 Deactivation/Intake Valve Control Circuit/Open | Do not keep driving |
P3457 | Cylinder 8 Deactivation/Intake Valve Control Circuit/Open | Do not keep driving |
P3465 | Cylinder 9 Deactivation/Intake Valve Control Circuit/Open | Investigate soon |
P3473 | Cylinder 10 Deactivation/Intake Valve Control Circuit/Open | Do not keep driving |
P3481 | Cylinder 11 Deactivation/Intake Valve Control Circuit/Open | Do not keep driving |
P3489 | Cylinder 12 Deactivation/Intake Valve Control Circuit/Open | Do not keep driving |
The definition
P3401: Cylinder 1 Deactivation/Intake Valve Control Circuit/Open.
P3401 is a manufacturer-specific powertrain code (the engine or gearbox). Its meaning is set by the carmaker rather than by the SAE standard, so a generic OBD-II reader will often show it as an unknown code or misread 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 every module in a VW, Audi, Skoda or SEAT — not just the engine — shows the live measuring blocks behind this fault, gives you the freeze-frame conditions it was logged under, and clears it once you have fixed it. It also does what a generic OBD reader cannot on a VAG: service resets, coding, adaptations, and Stage 1–3 flashing with your original file saved first.
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Common questions
What does P3401 mean?
P3401 means Cylinder 1 Deactivation/Intake Valve Control 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 P3401?
This class of fault can cause real mechanical damage if you keep driving on it. A persistent misfire also destroys the catalytic converter, which is the expensive part.