P2006 Code: Intake Manifold Runner Control Stuck Closed (Bank 1)

The intake manifold runner control (IMRC) system plays a crucial role in managing engine airflow. It helps improve engine performance and efficiency through the opening and closing of the butterfly valves in the intake manifold. When a vehicle’s primary computer detects a problem in this system, one of the trouble codes it may set is the P2006 code.

Each automaker may have a unique and complex IMRC system design, which means that the steps for testing and clearing this trouble code vary between different makes and models. Here is a guide about code P2006 to give you a basic understanding of this trouble code.

What Does the P2006 Code Mean?

Diagnostic trouble code (DTC) P2006 stands for “Intake Manifold Runner Control Stuck Closed (Bank 1).” It is logged when the powertrain control module or PCM directs the IMRC to open, but detects that the IMRC actuator for engine bank 1 is stuck in the closed position.

The PCM controls the operation of the intake manifold runner control (IMRC) system. It is made up of butterfly-shaped flaps that fit into the intake manifold runner. An electronic runner control solenoid opens and closes these flaps in order to fine tune air flow to the intake manifold.

Since these flaps are connected and opened with one motion, a problem arises when one of these flaps is stuck or binding. In some models, it may take multiple ignition cycles with a detected IMRC failure before the Check Engine Light is illuminated.

For an in-depth look at how various configurations of the intake manifold runner control work, you can read our technical discussion here.

If you want to know the possible causes of P2006, read the next section.

Note: The definition of code P2006 may be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.

What are the Possible Causes of the P2006 Code?

• Intake manifold runner control actuator failure
• Open or shorted wiring in the IMRC actuator solenoid control circuit
• Carbon buildup on the IMRC flaps or intake manifold ports
• Faulty MAP Sensor
• Restricted vacuum lines
• PCM failure

What are the Common Symptoms of the P2006 Code?

• Check Engine Light is on
• Hesitation upon acceleration
• Rough or fluctuating idle
• Rich exhaust
• Diminished fuel efficiency
• Engine surge

How to Diagnose the P2006 Code

Identifying the underlying cause of the P2006 code can be difficult, especially if you’re not confident with your automotive knowledge. In most cases, it would be best to bring your vehicle to an auto repair shop and seek the help of a professional for an accurate diagnosis.

Here is a video that can help give you a better idea on how this trouble code may be diagnosed:

How to Fix the P2006 Code

The P2006 code is a generic trouble code that may apply to various makes and models. While vehicles from different manufacturers may share common symptoms, the steps for diagnosis and repair vary depending on the car. For instance, the troubleshooting process for a P2006 Ford code may differ from a Mazda’s repair process.

If you’re an advanced DIYer who’d like to fix this code on your own, it will be helpful to refer to your repair manual or get factory vehicle repair information from an online subscription service.

Intake Manifold Runner Control (IMRC) Configurations

Manifold tuning is used for different reasons on different engine platforms. For example, in the late ‘80s Ford Taurus SHO engines (Mitsubishi design), the intake manifold runner controls would change the length of the manifold runner using butterfly valves. There were long runners and short runners, and at 4000 rpm, when most engines are just past their power curve, the SHO butterfly valves would divert the air from the long runners through the short runners, providing a boost of power.

This strategy has been used on smaller, less high performance engines as well, but IMRC on later models tends to operate differently, with the butterflies closed to restrict airflow at idle for better emissions. All butterflies on a given bank are moved by the same shaft. The butterflies don’t completely block airflow on these units. There’s a butterfly in each runner that has a small “bite” out of the corner of the plate so that even when the butterfly is closed, the air is forced to go faster from the manifold into the combustion chamber for increased turbulence, better atomizing fuel during idle and providing better flame propagation.

When the prevailing engine load requires more air, the butterflies are opened, allowing more air to flow.

There are other varieties of IMRC on different engines; these aren’t the only configurations.

Some of the earlier IMRC systems are cable or linkage operated, but many IMRC systems have the actuator(s) directly driving the shaft(s) that open and close the butterfly valves. Sometimes a feedback mechanism is used within the actuator and sometimes there is no feedback mechanism. When there is a feedback mechanism and the ECM/PCM detects that the IMRC actuator doesn’t respond to the command to open or close, a code will be set.

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