P2005 Code: Why Is Your Engine Losing Power?
You hit the gas pedal to merge onto the highway, but the car feels lazy. The Check Engine Light comes on, and your scanner reads P2005: Intake Manifold Runner Control Stuck Open (Bank 2). Don't panic—on many European and American cars, this is often a simple plastic part failure, not a blown engine.
What Does P2005 Mean?
Your engine needs to "breathe" differently depending on how fast you are driving.
- At Low RPM: Long, narrow air paths create torque.
- At High RPM: Short, wide paths create horsepower.
The Intake Manifold Runner Control (IMRC) uses flaps to switch between these paths. Code P2005 means the flaps on Bank 2 (the side of the engine opposite Cylinder 1) are stuck in the "Open" position. This kills your low-end torque and fuel economy.
🤔 P2005 (Air In) vs. P2003 (Air Out)
It is easy to confuse P2000-series codes. While P2005 is an Intake (Air Intake) problem, its cousin P2003 is an Exhaust (DPF) problem found on diesels.
If you have a diesel engine and are seeing codes related to "Efficiency Below Threshold," you are looking at the wrong guide. Check out our article on Diagnosing P2003 DPF Failures here.
The Common Culprit: Broken Plastic
Why is P2005 so common on vehicles like the Mercedes-Benz C-Class (M272 Engine) or Ford F-150 (5.4L Triton)? Poor material choices.
The actuator motor that moves the flaps is strong, but the little lever arm connecting the motor to the flaps is often made of cheap plastic. Over time, engine heat makes the plastic brittle, and it snaps. The motor keeps spinning, but the flaps don't move.
Other Causes:
- Carbon buildup jamming the flaps (common on Direct Injection engines).
- Failed IMRC Solenoid or Vacuum line leak.
- Wiring damage to the Bank 2 actuator.
How to Diagnose P2005 Without Disassembling the Engine
Taking off an intake manifold is a 4-hour job. You don't want to do that unless you are sure. Use the iCarsoft CR Ultra P to verify the failure first.
The "Active Test" Method:
- Visual Inspection: Pop the hood and locate the IMRC actuator (usually front and center on Mercedes V6s). Can you see a broken plastic arm? If yes, you found the problem.
- Bi-Directional Control: If the arm looks fine, plug in the CR Ultra P. Go to Actuation Test -> Intake Manifold Runner Control.
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Toggle ON/OFF: Command the flaps to open and close.
- Hear a click/whir but no movement? The internal linkage is broken.
- No sound at all? It’s likely an electrical issue (bad fuse, bad solenoid, or bad wiring).
Test Before You Wrench
The iCarsoft CR Ultra P allows you to manually activate intake runners, valves, and solenoids. Confirm the part is dead before you order an expensive replacement.
Frequently Asked Questions
Is P2005 serious?
It is not catastrophic, but it is annoying. Your car will feel sluggish, use more gas, and may fail emissions tests. Long-term, if the flaps broke off internally (rare but possible), pieces could enter the engine cylinder, causing major damage.
Can I just replace the plastic lever?
Yes! For many Mercedes and Ford models, aftermarket companies sell upgraded aluminum lever kits. This saves you from buying a whole new intake manifold ($600+) when only a $30 plastic piece is broken.
Which side is Bank 2?
Bank 2 is the side of the engine that does not contain Cylinder #1. On a standard V6 or V8 (Ford/Mercedes), this is usually the driver's side (Left) in the US, but always check your specific firing order diagram.
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