Check Engine Light Comes On With Reduce Engine Power

Rick from Sarasota Owner/Technician Posted   Latest   Edited  
2011 BMW X5 xDrive35i 3.0L (N55B30A) 8-spd (GA8HP45Z)—5UXZV4C56BL412446

I did a smoke test intake system, found no leaks, I did a visual inspection and found the flex pipe that comes from charge pipe to valve cover had a small break in it. The flex pipe has a two pin connector on it. I installed a new one and test drove. The check engine light came back on with same codes. Any info would be great at this time. I am using Autologic AssistPlus. It is a 2011 BMW X5 E70 XDRIV N55. VIN is 5UXZV4C56BL412446. Fault Code 2C57, Charging pressure control, plausibility Pressure too low Fault code 28A0, Throttle valve opening angle- intake pipe absolute pressure, comparison Pressure too high.


Mario from Weston



This would be a ton easier if we had code definitions. Seems trivial but if I'm asking for help, I'd personally try to make it as painless as possible for those reading. Does the oil cap get sucked into place when loosened with the car idling? May have a crankcase breather issue, very common. As you can imagine I'm not at work in front of my service info, but I'd like to help.

+3 Ð Bounty Awarded

Rick from Sarasota



That was the one of the first things we did remove the oil cap while running no different in engine running with oil cap off. I also added definition to fault codes as well. I tried to add the definition to fault code high lighted in orange.

0 Ð Bounty Awarded

Nicholas from Brooklyn



Hi, I found a TSB related to your problem. SI B12 16 11. I would rule out blocked exhaust, possible stuck open blow off valve

-1 Ð Bounty Awarded

Pam from Riverview



Good morning, Rick. With the electrical check complete (inc. voltage drop); the smoke test inclusive, there are a couple of items that should addressed, as well. 1) Recall campaigns: There are multiple recall campaigns for unmetered air issues, for this vehicle. We all know that smoke tests can deceive. Make sure the recalls were completed by BMW, before moving forward. 2) There are a couple of recalibration issues covering these symptoms, as well. Make sure these performance updates have been addressed. (My personal, educated guess/solution.) 3) Remember: These vehicles have heater issues with the PCV (another recall). Internally, is this component still intact? 4) With your borescope, take a look inside the intake. Carbon buildup can cause turbulence and give you a false positive, contributing to another, underlying issue; throwing you off track. 5) We are concentrating on the air intake. What were your fuel delivery readings (pressure, volume)? Fuel delivery issues are another, area of contention within BMW. Quick analogy: We all know that everyone in the group is wearing a shirt, but the color of the shirt? It's an educated guess. As these are educated suggestions. Hope these suggestions help you find the root of the issue. Take care Pam

+2 Ð Bounty Awarded

Jeff from Manchester



Isolate the turbo side from the intake and try to smoke it again under a little higher pressure. Also, there should be two vacuum reservoirs on the passenger side front of the engine compartment that are prone to cracking and nipples breaking off at the hose connections. Good luck.

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Edward from Middle Village



Have you checked the values of the pre and post throttle MAP sensors? I believe they should read equal at 1 atmosphere with ignition on engine off.

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