Fault codeP2004

MODERATE

Intake Manifold Runner Control Stuck Open (Bank 1)

What this code means

Intake Manifold Runner Control Stuck Open (Bank 1).

“Bank 1” is the side of the engine that holds cylinder number 1; “Bank 2” only exists on V and flat engines. An in-line engine has a single bank.

P2004 is a generic code: it means the same thing on every make. P2004 belongs to family P20xx — Fuel, air and emission controls. Its page explains how to read a code and groups all its codes by part.

Type of fault

The controlled part — solenoid, torque converter clutch — does not respond as commanded and stays stuck in one position. The cause can be electrical, but also hydraulic or mechanical: dirty fluid, a sticking valve. On an automatic gearbox, the fluid level and condition are the first thing to check.

Intake manifold flaps (runners and swirl)

Many engines have flaps in the intake manifold that change the length of the air passages or make the air swirl in the cylinders, to improve torque at low revs or combustion on diesels. An electric or vacuum actuator moves them, and a sensor checks their position.

What you notice

Lack of torque at low revs or of power at high revs, sometimes a rough idle.

How to check it

Soot and oil vapour seize the flaps, especially on diesels. Check the actuator, its vacuum hose if it has one, and its linkage: the flaps should move freely. On some engines a flap or its spindle can break off and fall into the engine, a known fault worth looking up for your model.

What to do

Have it checked this week. The car remains usable, but the fault will not clear itself and will fail the roadworthiness test.

Clearing a code switches the light off but repairs nothing: if the fault remains, the code comes back. Clearing a fault code yourself →

How to read this code

PPowertrain
2standardised code
0Fuel, air and emission controls
04P2004