Fault codeP2009

MODERATE

Intake Manifold Runner Control Circuit Low (Bank 1)

What this code means

Intake Manifold Runner Control Circuit Low (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.

P2009 is a generic code: it means the same thing on every make. P2009 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 control unit reads a voltage on this circuit below its expected range. Usual causes: a wire shorted to ground or broken, a corroded or loose connector, or the component itself. Check the wiring and connector before replacing the part — that is where many of these faults turn out to be.

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
09P2009