P3408
Cylinder 1 Deactivation Circuit Low Voltage
The engine control module has detected low voltage on the cylinder 1 deactivation control circuit. Variant of P3404 reported on platforms with separate diagnostic ranges.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Wiring shorted to groundCommon
- Solenoid internally shortedPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Cylinder Deactivation Solenoid
- Engine Wiring Harness
P3408 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.