P3403–P3491 Cylinder 1 Deactivation/Intake Valve Control Circuit Low
The voltage on this circuit is sitting near zero. Typically a short to earth, or a sensor that has failed to its low end.
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 |
|---|---|---|
P3403 | Cylinder 1 Deactivation/Intake Valve Control Circuit Low | Do not keep driving |
P3411 | Cylinder 2 Deactivation/Intake Valve Control Circuit Low | Do not keep driving |
P3419 | Cylinder 3 Deactivation/Intake Valve Control Circuit Low | Do not keep driving |
P3427 | Cylinder 4 Deactivation/Intake Valve Control Circuit Low | Do not keep driving |
P3435 | Cylinder 5 Deactivation/Intake Valve Control Circuit Low | Do not keep driving |
P3443 | Cylinder 6 Deactivation/Intake Valve Control Circuit Low | Do not keep driving |
P3451 | Cylinder 7 Deactivation/Intake Valve Control Circuit Low | Do not keep driving |
P3459 | Cylinder 8 Deactivation/Intake Valve Control Circuit Low | Do not keep driving |
P3467 | Cylinder 9 Deactivation/Intake Valve Control Circuit Low | Investigate soon |
P3475 | Cylinder 10 Deactivation/Intake Valve Control Circuit Low | Do not keep driving |
P3483 | Cylinder 11 Deactivation/Intake Valve Control Circuit Low | Do not keep driving |
P3491 | Cylinder 12 Deactivation/Intake Valve Control Circuit Low | Do not keep driving |
The definition
P3403: Cylinder 1 Deactivation/Intake Valve Control Circuit Low.
P3403 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:
- Unplug the sensor. If the reading jumps to full scale, the wiring is fine and the sensor has failed low.
- Check the sensor's 5V supply and its earth before condemning the sensor itself.
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 P3403 mean?
P3403 means Cylinder 1 Deactivation/Intake Valve Control Circuit Low. The voltage on this circuit is sitting near zero. Typically a short to earth, or a sensor that has failed to its low end.
Can I drive with P3403?
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.