TPS Codes, Limp Mode
 

Hey everyone!
I have a 2008 550i Msport, that has been having this problem for around 2 months. Earlier, it would reset to normal with a simple restart. Then going into the colder weather, It started happening every cold start, and wouldn't return to normal with a restart. I would have to let the car sit after running for around 20 minutes. Now, it won't come out of limp mode.
Today (and also before when the problem first arose), on the highway I received:
DBC Malfunction!
Start Off Assistance Malfunction!
Engine Malfunction!
EML on

I pulled codes P0120, P0221, and a pending code, C0300.


I replaced the Throttle body harness (Part #: 12 51 7 602 973) and it did not seem to fix the problem as others have stated.
All fluids are topped off as well.
AFTER the repair:
With the TB plugged in, the engine was still in limp mode, although did not limit RPMs.
With the TB unplugged, the engine limited RPMs to 1900. So from what it seems, the harness is wired correctly (i triple checked!)
The next place to go is the throttle body, from what i've seen.

I have searched, and although i am experience what some others witih the same problem have experienced, I don't know where to go from here.
A refurbished throttle body is 280+tax from autozone, and I will need my car fixed ASAP!
Does this sound like a TPS problem? or does it seem intermittent?

would like to get others opinions on this, and can provide further information as well.
Thanks! ~Kal

I just recently (3 weeks ago) fixed my car after suffering through the exact same thing. I replaced the throttle harness, throttle body (be sure to get an OEM one, not a refurb), alternator and battery. Still didn't fix the problem, gave up and took it to an independent. It took him a couple hours but he eventually rechecked the throttle harness, rewired it and had to do a DME reset. That's cured it and the car is running much, much stronger than before it started malfunctioning.
You can get a brand new OEM VDO throttle body for the same price as that rebuilt one:
BMW Throttle Body Assembly - E53 X5, E60 545i, E63 645ci, E65 745i w N62 Engine

I have never heard of this issue before. It is surprising to me that 08s are needing a TB change so early. Those usually do not go out at least within 10 years 200k miles.

Thanks! How do i perform a DME reset? Is it as simple as disconnecting the battery for 30 mins - a couple hours? I tried unplugging the battery from the negative side, waited 20 minutes, and restarted to no avail. Any other tricks I can try?
I have a new TB and Pedal assembly on the way. Will return whichever doesn't need to be replaced.

Sean, this is actually a pretty common problem on the N62. Just do a search on the X5,5,6,&7 boards for "throttle body"...basically any car that uses the N62. The only thing this throttle body has to do is keep the flap open when running and it fails to do that basic function after awhile. Well, it actually acts as a throttle backup if Valvetronic fails, so I guess it's doesn't just have a basic function, lol.


DME reset requires something like INPA or some other dealer/indy software as far as I know. Just unplugging the battery ain't gonna cut it. You could possibly have the throttle body harness wiring mixed up as well...turns out it is not a direct install because you could have the wire/pin combination mixed up. The repair harness wires and the wires coming from the DME don't have matching colors (which is stupid) so mixing it up is easy to do. I'm betting that is part of your problem...that was definitely mine. A quick test is to check the function of the throttle body after you put the car into "run" (ignition on but not started). I think the throttle body flap should open after a couple of seconds. If it does nothing, there is no communication from the DME to the throttle body or the throttle body itself is bad, causing the limp mode.

Yes!! The wire colors pissed me off! Although i did match them from the original pins. (matched each pin). I'll give the throttle body test a go and let you know how that goes!

I never knew. Something so premature I would talk the dealership in replacing under the good faith warranty. The many times that have saved me from spending a lot of money for something that should not of failed so early. I hope you get things worked out.

Ok. I've replaced everything i can think of being the problem. Pedal assy, as well as TB and the TPS harness. When i start ignition, i can hear and see the throttle body open and close. I cleared all codes but nothing has changed, now it's just in limp mode!

I honestly don't know what else this could be! any advice? :(

I think it's time to take it to an independent. Have you noticed the voltage as it's running? seems like you could possibly have problems with voltage. How many miles are on the car? The alternators are the other source of problems on these cars as any little deviation of a steady 14 or so volts will cause a lot of things to go haywire. There is a way to access the voltage in the hidden menu in the dash (you'll have to google it). Anything less than a steady 14-14.6 volts while running and under load will point to the need for a new alternator and possibly battery.

I'll tell you how coincidental your post is:
After running perfectly and strong for the past 3 weeks after repair, I encountered a "soft" limp mode....no CEL but power was lost with almost no response to throttle. A restart cleared it instantly. It happened 2 more times and last night, it threw a CEL with the half-engine fault and reduced power. It wouldn't' reset after a restart this time and there was a loud hiss/squeal coming from somewhere under the hood. Had the exact same rough idle and surging that started all of this crap. I had Carly app hooked up this time while it was running and voltage was all over the place. I had my old alternator rebuilt instead of replacing with a new one before all of this happened a month before and I think the voltage regulator isn't working right. Already set up an appointment with my indy for a new OEM alt install as he thinks that is the problem ($1000:angry:).
Long story short, check your voltages and see if they are a steady 14.6 or so. If not, that could be the cause of the limp mode. Just throwing out another possible issue to check, but I by all means hate encouraging throwing parts at problems like these. I'd get an independent to look at it and fix it once and for all. Good luck.

I checked the voltage, it seems to be running around 14.6, and never drops below 14.2, and highest i've seen is 14.8 under full rpm.
I also tried connecting my father's M4 via jump cables to get a more steady current, but nothing.
I agree, it is time to take it to an indy. I'm able to drive the car now, it is just slow and stuck in limp mode!
Anyways, will be taking it in ASAP (most likely monday) will let you all know how it goes!

Yes, please post your results here so that it can be referenced by others in the future! Glad you are taking it to an Indy as I was in the exact same situation and there was nothing more that I could do to fix mine.

So just a quick update...my POS car is still experiencing limp mode. I've had the alternator just replaced with a new OEM unit, new registered AGM battery, previously installed a new OEM throttle body, and new wire harness. So $2500 later, the car still is going into limp mode. Cruise along and the throttle just stops responding and slowly but surely, lights pop up on the dash. Dealer and Indy are stumped and suggest DME and engine harness replacement. Basically gonna give up on this car. Good luck to anyone else that can figure out the issue...

None of the repairs should be done unless there is a root cause identified. I'd say find a new Indy who has a lot of experience diagnosing electrical issues.

:heart:those were the repairs completed based on the codes given by the car. As the repairs were completed, those codes no longer appeared and now I'm getting a soft limp mode without a CEL most times....just no throttle response and max RPM at 1300. Restart will clear it. Just yesterday it went into limp with the half engine and DSC fault and as I was pulling over to restart, it cleared. Just random crap.

Limp mode
 

Hello everyone, I am knew to hear as well my new/used purchase 2006 525xi. 69000 miles know at 70000.I had exactly a month know and I love it. I am the third owner. Except the 20th hour Idrive came on said pullover. Long story short dealer replaced the Tstat and water pump thank goodness for my 60 day 2500 mile warranty. 2nd week in when I would start it the Rpms would go up to 1400rpm then back down to 600rpm, a day or two later service engine soon light came on. This is not my daily driver I am fortunate enough to have company van to take home and a 2006 tundra I've owned since 2008. My performance was not their car didn't feel right sluggish. I brought back to dealer (having had several codes pop up checked by local auto store). Running great know they replaced the dorman variable timing actuator solenoid 1) exhaust bank one, and 2) intake bank 2. I hope this helps anyone with future problems. The dealer only charged me the $100.00 deductible for second problem.

Another follow up for future searches....another harness was installed as the one I hacked up during installation and was attempted to be repaired by my Indy was too messed up to reuse. This was why I continued to have problems. He purchased all new harness and nearly rewired the entire throttle wiring. Been running like a champ since last post!

I have a 2008 E60 550i M sport package as well. 75k mileage. 3 weeks ago the car went weak on the throttle up a hill. Then the dash lit up like Christmas. So I pulled over, turned off the car and waited 10 seconds Problem was fixed. About 1 hour later and 60 miles more, the car went into limp mode. The turn off and start up again didn't work. So I took it to the dealership. They replaced the throttle body and wiring harness and the battery. Problem solved. After 3 weeks the car drives great, but the idle is rough and sputters a lot. Going to check the MAF and clean it. Then check the alternator and go from there.

You took it to the dealership and you still are troubleshooting. Take it back I guarantee they just replaced parts to get it driving again. Battery and throttle body, does not match what was going on. I would say probably the battery needed to be replaced and if it was the battery they should of tested the alternator charged the battery and probably found out it originated at the alternator. Now you have sputtering meaning they cracked a hose changing the throttle body. Take it back and demand they fix it. If you are having the electrical problem anymore they will refund you and fix the actual issue under goodwill warranty charging you just for the part.

Faults 2CF8, 2CF9, AND 2CFA were called up. I had them replace the battery first. But the codes reappeared. They replaced the TB and harness and that made it work. That was at 72406 mileage. I am now at 74,700. I don't feel there sufficient reason to assume their work was wrong.

But the weird idle, which by the way, fixed itself when it got cold last night(below frost warning alarm of 37 degrees). It maintained a constant 700 rpm with little to no fluctuations.

Ok. Know I'm understanding. Did not know you had them change the battery. You might want to check for vacuum leaks. That is what it sounds like to me.