P2004 Intake Manifold Runner Control Stuck Open (Bank 1)

P2004 means the intake-manifold runner control (the flaps that change intake length/swirl) is stuck in the open position on bank 1. The module commands them closed at low RPM but the feedback shows they did not move.

Code details

Generic OBD-II · P2

System: Fuel / Air
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace the whole intake manifold before confirming whether the fault is a stuck actuator, broken linkage, or a position-sensor reading.

Symptoms of P2004

Check-engine light.
Reduced low-end torque or a slightly rough idle.
Possible small drop in fuel economy.

Common causes of P2004

A stuck or failed intake-runner actuator.
Broken or disconnected runner linkage.
Carbon build-up jamming the flaps.
A runner position-sensor or wiring fault.

Useful checks before replacing parts

Inspect the runner-control actuator, linkage, and flaps for binding or breakage.
Check the actuator command versus the position-sensor feedback live.
Look for carbon build-up jamming the runner flaps.

Related OBD-II codes

These nearby fuel / air entries can help compare wording and pin down the fault area.