Skip to content

P2004 – Intake Manifold Runner Control Stuck Open Bank 1 (OBD2)

P2004 means "Intake Manifold Runner Control Stuck Open Bank 1". The control unit sees an open circuit: the electrical connection to the intake manifold tuning valve is interrupted, so no current can flow when the component is commanded or read.

Last updated

P2004 quick summary

Fault codeP2004
MeaningIntake Manifold Runner Control Stuck Open Bank 1
SystemPowertrain (Engine & Transmission)
VehiclesGeneric OBD2
SeverityLow
Can I drive?Yes. You may notice slightly less power at certain engine speeds.
Repair cost€20 – €600

How the intake manifold tuning valve works

The intake manifold tuning valve changes the length or path of the intake runners to improve torque at low rpm and power at high rpm; these codes cover its control circuit.

Many petrol engines have a variable intake manifold: a flap or valve switches between long runners (more torque at low rpm) and short runners (more power at high rpm). It is operated by a vacuum actuator controlled by a solenoid, or by an electric motor with a position sensor.

Codes P0660–P0665 report open, low or high faults in the tuning valve control circuit for bank 1 and bank 2. If the valve does not switch, the engine loses some torque or top-end power, but usually runs normally otherwise.

Typical causes are a failed solenoid, cracked vacuum hoses, a sticking flap or broken linkage, and wiring problems.

Bank 1 is the side of the engine that contains cylinder 1. In-line engines (three, four, five or six cylinders in a row) have only bank 1.

Symptoms of P2004

  • Check Engine light on
  • Reduced power at low or high rpm
  • Rattle from the intake (broken linkage)
  • Slightly higher fuel consumption
  • Often no noticeable symptoms

Most common causes of P2004 (most likely first)

Mechanic's Pro Tip

On many engines the plastic linkage of the intake flaps breaks long before the actuator fails – look at the linkage before buying a new actuator.

  1. 1.Unplugged, loose or corroded connector

    Most likely

    Often after previous repair work in the area.

  2. 2.Broken wire in the harness

    Typical at bends, near the engine mounts and where the harness rubs on brackets.

  3. 3.Burnt-out winding or internal break in the intake manifold tuning valve

  4. 4.Failed tuning valve solenoid or actuator

  5. 5.Cracked vacuum hose

  6. 6.Sticking flap or broken linkage

  7. 7.Control unit driver fault

Step-by-step diagnostic guide

  1. 1

    Read codes

    Read all codes and note which bank is affected.

  2. 2

    Measure resistance and continuity

    Unplug the intake manifold tuning valve and measure its resistance across the terminals. An infinite (OL) reading confirms an internal break. If the component is fine, check each wire back to the control unit for continuity.

    Multimeter: Solenoids and heaters typically read a few ohms to a few dozen ohms; "OL" means open. Wire continuity: below about 1 Ω.

  3. 3

    Command the valve

    Use the scan tool to switch the valve and watch or listen for movement.

  4. 4

    Check vacuum and solenoid

    Check the vacuum supply and hoses; measure the solenoid resistance.

    Multimeter: Many tuning valve solenoids read about 20–40 Ω; check the specification.

  5. 5

    Check the linkage

    Check that the flap moves freely and the linkage is intact.

  6. 6

    Repair and verify

    Replace the faulty part and clear the codes.

Frequently asked questions

Can I keep driving with P2004?

Yes. You may notice slightly less power at certain engine speeds.

How much does it cost to fix P2004?

Typical repair costs are 20 € – 600 €, depending on the cause and the vehicle. The most common fixes are: unplugged, loose or corroded connector; broken wire in the harness; burnt-out winding or internal break in the intake manifold tuning valve. Always confirm the cause with the tests above before buying parts.

Is an intake manifold tuning valve code serious?

Usually not; the engine loses some performance but runs normally.

Is it the same as swirl flaps?

Similar but not the same: tuning valves change the runner length, swirl flaps change the air flow pattern in the cylinder. Some engines have both.

What is the difference between P2004 and similar codes?

P2004 belongs to a group of codes for the same component that differ in the type or location of the fault: P0663 – Intake Manifold Tuning Valve Control Circuit (Bank 2); P0664 – Intake Manifold Tuning Valve Control Circuit Low (Bank 2); P0665 – Intake Manifold Tuning Valve Control Circuit High (Bank 2); P2005 – Intake Manifold Runner Control Stuck Open Bank 2; P2006 – Intake Manifold Runner Control Stuck Closed Bank 1; P2007 – Intake Manifold Runner Control Stuck Closed Bank 2. The tests on this page apply to the whole group; the type of fault tells you where to start.

Related fault codes

This guide is for information only. Working on vehicles can be dangerous — if you are unsure, have the car checked by a qualified mechanic. Values can differ between model years; always check the manufacturer's repair information.