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Hi all, my friends 2006 pre lci M5 has been going into limp mode, it shows three codes which are
27DA altimeter fault.
2B57 air-mass sensor, plausibility
2796 throttle actuator- test, lower stop.

All fuses and relays are fine, i found water in the brake servo which i have since changed along with the master vacuum pump next to the servo, and still it persists! Sometimes the car will do less than a mile before limp mode and other times over 15 miles.

And ideas??
TIA
 

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Any luck with this? I have the exact thing going on with mine. What are your LTFTs looking like? Mine are pretty bad, -20/-17. O2s and maf seem to function properly. From what I've been reading, it can be MAF sensors, vacuum leak, possible fuel pump/regulator issues, or maybe throttle actuators. It's a real downer when I hear the beep and feel the power loss.
 

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Thanks Matthew. That's what I'm in the process of doing right now. I have them both pulled and paid $32 off Amazon for 2 sets of gears. I have them mounted on the shafts, just gotta drill and pin them. Hoping to have her back up and running in a couple days.
 

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Better go ahead and grab an OEM or two and keep in the trunk.
If you do some searching you will see that many repaired TA's don't last long.
 

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I appreciate it guys. Still have the engine malfunction after changing gears and reinstallation of the actuators. Now, I'm looking at a P2629(bank 2 sensor 1)/27B4(misfire cyl ?, and 2B57(Mass Air Plausibility). Gonna change out my O2 sensor today and see if it fixes it.
 

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Alright...so like I said. Reinstalled actuators after changing gears. Here's what I've done so far:
New Maf sensors
New Bosch B1S1 O2 sensor
New Factory Air Filters
New Fuel Cap
New DMTL pump
Still going into limp mode with a redline of 7k(increased emissions and engine malfunction/reduced power).
-Codes are: 2B57, 2796, 27CD as culprits
-Generic OBD codes are: P010, P010B, and P0161(bank 2, sensor 2)<---downstrean O2 shouldnt cause this but will get changed soon.
-Live data is showing when I hit the throttle(WOT)....throttle actuators go up to 100% on both banks.
-This makes me think they are functioning properly mechanically and electronically.
Hypothesis: Sneaky VACUUM leak. Thinking the Vacuum leak is popping the other codes.
*I do know that there is still a possibility that it's the actuators due to the fail rate of these things* mosfet circuits
So, gonna be searching for leaks next.
I've seen so many posts that just drop off right when it's getting good. So...I will make 100% sure I will finish this post with the culprit when I find it; in hopes of helping someone else.
 

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Alright...so like I said. Reinstalled actuators after changing gears. Here's what I've done so far:
New Maf sensors
New Bosch B1S1 O2 sensor
New Factory Air Filters
New Fuel Cap
New DMTL pump
Still going into limp mode with a redline of 7k(increased emissions and engine malfunction/reduced power).
-Codes are: 2B57, 2796, 27CD as culprits
-Generic OBD codes are: P010, P010B, and P0161(bank 2, sensor 2)<---downstrean O2 shouldnt cause this but will get changed soon.
-Live data is showing when I hit the throttle(WOT)....throttle actuators go up to 100% on both banks.
-This makes me think they are functioning properly mechanically and electronically.
Hypothesis: Sneaky VACUUM leak. Thinking the Vacuum leak is popping the other codes.
*I do know that there is still a possibility that it's the actuators due to the fail rate of these things* mosfet circuits
So, gonna be searching for leaks next.
I've seen so many posts that just drop off right when it's getting good. So...I will make 100% sure I will finish this post with the culprit when I find it; in hopes of helping someone else.
Anyway you can swap the 'good' actuator with the bad to see if the faults change sides? My money is on the PCB in the actuator being cooked.
 

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As for me...I bought some new throttle body actuators from FCPEuro because of that 2796 code. Didn't fix the issue, but I rationalize it bcuz of the lifetime warranty...anyway. I still have the exact same issue. On a hot startup, I can throw it into M and ITS GREAT. Usually within 1-3 miles, it pops the 7k RPM malfunction again. I found an Indy mechanic out here in Jax Florida and they know what they're doing. So, as much as I love troubleshooting and DIY, I may have to take it to them.
 
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