P2005 on Mercedes-Benz: How to Diagnose & Fix
Intake Manifold Runner Control Stuck Open (Bank 1)
1 Mercedes-Benz model · 2 documented issues · 1 critical · $400-$2,500 repair
P2005 on Mercedes-Benz by model: symptoms, diagnosis and fix
The M272 3.5L V6 intake manifold uses plastic swirl flaps on a shaft driven by a small plastic actuator lever. Heat-cycling makes the lever and the shaft bushings brittle; the lever cracks or the bushing wears through, so the flaps no longer move and the ECU sets P2004/P2005 (intake runner stuck open) plus P0521-type actuator complaints. Owners report a rough or hunting idle, a noticeable flat spot off idle, and reduced low-end torque. The bigger risk is that a broken flap or its retaining clip drops down a runner and gets ingested by a cylinder. Because the manifold is a single plastic assembly, Mercedes only sells the whole manifold, which is why owners on BenzWorld/MBWorld debate repair kits versus replacement.
Common Symptoms
- Check engine light with intake runner codes
- Rough or unstable idle
- Hesitation and reduced power below 3000 rpm
- Rattle or buzz from the top of the engine
- Occasional misfire codes
How to Fix
Confirm with live data that the swirl flap actuator is commanding but the shaft is not moving. The durable fix is a complete intake manifold assembly (updated part) with new gaskets. A cheaper and widely used route is an aftermarket repair kit with an aluminum lever, arms and bushing/rod pieces - this works when the manifold body and flap shaft are still sound, but it can fail again if the internal bushings are already worn. While the manifold is off, clean carbon from the runners and inspect that no flap fragments have gone into a cylinder.
Sources for this issue (3)
On the OM642 V6 diesel used in the E320 CDI/BlueTEC and E350 BlueTEC, the swirl-flap actuator motor sits low on the intake and is directly under the turbo intake seal, which is itself a known oil-leak point. Oil drips onto the motor and kills it, and the plastic linkage arm between the motor and the flap shaft snaps. At the same time EGR soot builds up in the intake runners until the flaps physically seize. The result is P2004-P2007 / P2015-type intake runner faults, limp mode capping the engine around 3000 rpm, rough idle and poor throttle response. Owners on BenzWorld and MBClub consistently report that replacing the actuator motor alone without cleaning the intake results in a repeat failure within 20,000-40,000 miles.
Common Symptoms
- Limp mode / power cut around 3000 rpm
- Check engine light with intake runner control codes
- Rough idle and poor throttle response
- Black smoke under acceleration
- Oil residue around the intake actuator motor
How to Fix
Remove the intake manifolds and physically clean the soot from the runners and flaps, replace the swirl flap actuator motor and the linkage rod (aftermarket metal rod kits are common and hold up better than the plastic original), and critically, fix the turbo intake seal / oil leak above it or the new motor will be soaked again. Some owners in high-mileage cars go to a swirl-flap delete, but that is not emissions-legal in the US. Address the EGR cooler and intake condition at the same time since the manifolds are already off.
Sources for this issue (3)
P2005 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P2005 mean on a Mercedes-Benz?
P2005 stands for "Intake Manifold Runner Control Stuck Open (Bank 1)." This code means the engine computer detected that the intake manifold runner control (IMRC) for Bank 1 is stuck in the open position. The IMRC system uses flaps inside the intake manifold to change airflow length and velocity depending on engine speed, improving low-end torque and high-end power. When the runners are stuck open, the engine can't optimize airflow, which may cause rough low-speed running, reduced power, and a check engine light. It is not an immediate breakdown risk but should be addressed to restore performance and pass emissions. On Mercedes-Benz it is documented across 1 model: E-Class.
What are the most common causes of P2005?
The most common causes of P2005 are: Carbon buildup jamming the runner flaps, Stuck or seized IMRC actuator, Broken or disconnected runner control linkage, Failed vacuum-operated runner actuator or leaking vacuum line, Faulty intake manifold runner position sensor, Wiring or connector fault to the IMRC solenoid, Damaged intake manifold runner assembly. The specific cause varies by vehicle.
How much does it cost to fix P2005 on a Mercedes-Benz?
Published repair estimates on Mercedes-Benz range from $400 to $2,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P2005 on a different make?
View P2005 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.