What does the fault code P2006 mean in a Mercedes Benz car?

This blog will explain the meaning of the fault code P2006 in a Mercedes Benz car. The following questions are also answered in the blog: what are the causes of the P2006 fault code? Which models are affected by the P2006 fault code? how to diagnose the P2006 fault code? How much does it cost to fix the P2006? 

What does the fault code P2006 mean in a Mercedes Benz car?

The fault code P2006 in a Mercedes Benz car means the variable intake manifold tumble flap has a malfunction. The tumble flaps in the variable intake manifold are used to direct the flow of intake air in a long or short path. This change in the direction improves the cylinder charging and gives the M272 a turbocharging effect even though it is naturally aspirated.

The tumble flaps are connected to three vacuum cells via plastic levers; when the vacuum is applied to the vacuum cells, the levers operate the tumble air flaps in the intake manifold.

M 272 is a port injection engine, the fuel is injected into the intake manifold, and when the intake valves are opened; the tumble flaps improve the mixing of the air-fuel mixture.

The flaps are spring-loaded and only need a vacuum to hold them in the open position. 

The open position does not produce a swirl in the air-fuel mixture. The cylinder is charged naturally during the intake stroke.

What are the causes of the P2006 fault code?

The causes of the P2006 Fault code are given below

• Broken linkage between the vacuum cell 

The tumble flap is controlled by three vacuum cells located in the front of the intake manifold. All three vacuum cells have separate arms which are connected to the left and right tumble flaps in the intake manifold.

These arms are made from plastic and the flaps are spring loaded so the engine control unit only needs to actuate the tumble flap in one direction. The vacuum cells are connected to the electro-pneumatic actuator and two hall sensors determine the position of the intake manifold tumble flaps.

The linkage breaks as dust and soiling near the intake manifold and the cylinder head start to accumulate. The dirt and soiling jam the mechanism and eventually brakes the runner lever or any one of the links connected to the vacuum cell.

Mercedes Benz provided a repair kit in a few markets but due to reliability concerns, it is no longer available as a child part. The complete intake manifold is replaced and the vacuum cells come with the new part.

Mercedes Benz has also updated the mechanism and made it more sturdy. If there is a leak in the intake manifold gasket it must be rectified before too much dirt is collected in the tumble flap mechanism.

• Vacuum leak

The vacuum actuators use rubber hoses connected to the intake manifold. If there is a leak in the vacuum hose then there will not be sufficient vacuum supply in the cells. Without the vacuum, the linkage cannot move against the spring load.

A Visual inspection is performed to identify leaks in the vacuum lines. Alternatively, an automotive smoke detector can also be used to identify a leak in the vacuum lines. The tumble flaps can be actuated from a diagnosis scanner after the leak in the system is rectified.

• Fault in the electrical lines of the hall sensors

Two tumble flap position sensors are located at the back of the intake manifold. The engine control unit is directly connected to the individual sensor with electrical lines. If there is an open circuit or short circuit in the electrical lines, ECU cannot detect the change in the position of the tumble flap.

The angle of the tumble flap is controlled by the engine control unit. If more air mass is present and the engine speed is high, the swirl angle is also sharp so that the air-fuel mixture can mix more easily.

Which models are affected by the P2006 fault code?

Mercedes Benz used the variable intake manifold in the new generation of the V6 and V 8 engines named M272 and M273 respectively. The only difference between the M273 is the addition of two cylinders and the lack of a balancer shaft in the crankcase.

Mercedes Benz used the M272 and M273 engines in C, E, S, CLS, and R models but the fault P2006 is mainly observed in the following models.

• C Class model series W204 pre-facelift (C250, C 280, and C 350)
• E class model series W212 pre-facelift (E280 and E 350)
• S Class model series W 221 (S 350 and S 400 hybrid)

The fault code is common in models with high mileage and usually results in engine check light on in the instrument cluster. The performance of the engine is also reduced as the cylinder charging is inconsistent.

The M272 also feels underpowered in bigger models like the S Class. Therefore, the fault code P2006 must be rectified as it affects the performance and the fuel efficiency of the model.

How to diagnose the P2006 fault code?

The procedure to diagnose the P2006 fault code in Mercedes Benz is given below:

• Perform an initial quick test and read out the fault memory of the engine control unit.
• Perform a Xentry guided test for the fault code and carry out a visual inspection of the intake manifold tumble flap levers.
• The tumble flap actuating levers can be operated from the diagnosis scanner.
• If the actuation is not okay then check for any vacuum leak in the hoses.
• If all the vacuum hoses are okay then replace the intake manifold and renew the intake manifold gaskets.
• Perform resetting of adaptation data so that the engine control unit can adjust the mixture formation according to the new intake manifold.

How much does it cost to fix the P2006 fault code in Mercedes Benz?

The cost to fix the P2006 depends on the cost of the spare parts, in the authorized dealership the intake manifold is completely renewed to rectify the P2006 fault code. However, individual parts of the tumble flap actuator can be purchased in the aftermarket. The following table contains the cost and the spare parts.

Mercedes Benz no longer provides child parts for the repairs of the intake manifold. Therefore, in authorized dealerships, the complete intake manifold is replaced. The intake manifold gaskets are also renewed while replacing the intake manifold.

It is recommended to replace the complete intake manifold and then install the repair kit consisting of runner levers and vacuum cells. Mercedes Benz also provides a 2 years parts warranty on the intake manifold.

Conclusion

This blog explained the meaning of the fault code P2006 in Mercedes Benz cars. The M272 and the M273 engines were widely used until more modern direct injection M276 and 278 engines were introduced across all the product range in Mercedes Benz. The fault code P2006 mainly affects the M272 and M273 engines and it is easy to diagnose.