EML Light; Randomly goes off

I have 2001 E46 330i with 100K; Car runs really great most of the time; I can drive 4 days straight without issue. Then for some unknown reason the EML light fires off and the car is in limp mode (seems to mostly happen when coasting down hill; resets with engine restart). My mechanic has replaced all error code items like gas petal, intake sensors etc., reprogramed computer but nothing seems to fix the problem. The only item not replaced is the computer. Replacing the computer makes no sense to me as it runs fine most of the time otherwise. This has been occuring for 6 months now... Anyone having similar problem? My mechanic says that other shops across the country have had similar problems that they cannot fix either?

First thing to do is look at all of the repair orders and post a list of what was done and what was replaced. Then we'll go from there. The only reason I say this is that I might tell you, "It's the muffler bearings" and then you will come back and tell me, "The muffler bearings were already replaced." In essence, it just saves time. Also, when I see things like "intake sensors" that a general statement. Does that mean, intake temp sensor or MAF sensor?

Stock throttle body? Low Voltage?

idk if this will help but when i installed my sprint booster i had to break the white clip on the side of the gas pedal and that allows the pedal to slip to the left... i was driving and my floor mats were under my feet and for some reason my eml light went on and i checked everything and didn't know what it was. i then checked the pedal and it went of to the left just a tad.. i turned of the car refit it then started up again and didn't notice anything.... now very slim chance this is it but the only reason im sharing is because it happened like a day after the SB was put in.. Just go check your gas pedal real quick for fitment

Ok the list of repairs done so far that I know about in the past year. The mechanic claims to have done every check he can thing of. He works only on BMWs.

- New spark plugs (I replaced)
- Air pump hose (I replaced)
- Crank vent valve and vent pipes
- Idle Control valve
- Mass Air Sensor and Intake Bellows.
- Gas Petal - the check this for problem as mentioned by one thread
- All wire harnesses checked.
- Alternator and battery (not related per se but I had to have it replaced again from first repair because it would get low voltage at high RPMs; seems ok now).

This is all I know was repaired. Other things may have be tried by mechanic. I switched gas as last thought as I always buy from same station.

When you say, "limp mode" what is that exactly. Reason I ask is because limp mode could be the car is dropping a cylinder (i.e. #3 not firing) or is it the car runs smoothly but is at a loss of power (i.e. only 60% throttle)?

Have you has someone check the actual BMW error codes from the ECU ? Again, there are the generic P-codes but then there are the more specific BMW codes. The BMW ones are more detailed and will help diagnose a problem much faster.

I mean that throttle change is reduced by the computer. If you press the pedal to the floor, the car will slowly accelerate to speed. Engine runs fine. Interesting I found the cruise control will not work either. I believe this is all for safety so that you don't have run away car. Since the gas petal is just electronically tied to the engine (e.g. no cable to the intake). EML light identifies that the computer is in this "limp" mode. I call it "limp"; maybe there is more technical term.

Still having problem. I get error code on non-BMW OBD2 reader of P1501 -Vehicle Speed Sensor Out of Self Test Range. Does anyone know where this sensor is? Not sure why this fires off during driving?

I used to get this, along with check engine light, dsc and brake light.
I took it to my mechanic who has the BMW GT1 scanner, he was able read the entire car, well basically every module controller was saying low voltage. I ended up frying my alternator due the sounds I had in the car.
Once I replaced the alternator and cleared all the codes, i never had none of the lights come on the dash

i read the title as FML light....hhehehe

Originally Posted by alwaysbored786

i read the title as FML light....hhehehe

bahahaha good one

It could be your throttle position sensors going bad. If the computer starts to read bad signals for between the sensors it will eventually put the car into Emergency mode. That's the EML light. Depending on what the problem is, the computer will decide which Emergency mode you need to be in. There are a few different modes and I've been in one that limited my speed to 20mph.

In my case it was both throttle position sensors. Replaced them and it has been perfect since.

Note: The throttle pedal works the same way with the drive by wire throttle system and if it starts to go bad it can cause the same thing.

I had bought a new gas pedal and two TPS sensors. Ended up not needing the gas pedal so if this is you problem I'll sell mine for $80.00

Hope this helps.

I have had the gas petal replaced and no change in the problem. I have had the Mass Air Sensor changed which I thought took the place of the throttle plate. So I'm not sure what the throttle position sensor is. The repair shop claims to have tried fixing them all... Since the cruise control does not work maybe it really is the speed sensor...

EML light means there is a "drive by wire" fault. in most cases when its the throttle position sensors the dash will light up like a christmas tree, EML,DSC,AND BRAKE lights will illuminate and car will go into a trottle limiting state until you turn the car off and restart it.

that sounds like a problem I had with mine a few years ago except it would throw the check engine light. The car would run in limp mode and I replaced the camshaft position sensor (intake) and the car ran great again. A couple of years later I had to replace the camshaft position sensor (exhaust)

TPS #1 is the one by the oil filter. Easy to check if you have a code reader by clearing the codes then start the car and unplug the connector to that sensor then read the code. It will read "throttle position sensor #1" and you should also read a code that says "throttle position cross check". Both sensor have to work because every time you start the car the computer reads the initial position on both and they have to match.
TPS #2 is under the air box attached to the back of the throttle actuator.(2003 M3 in this case, it may be different for other 3 series) That's the one that gave me some trouble to get to because you have to remove the whole thing air box out of the way.

Now, if you read a code that says pedal than it is the accelerator pedal itselt that could be bad. I bought the pedal brad new before doing my research and found out that it was the other two sensors that were bad. They start to go bad slowly because it is basically a potentiometer where the electrical contacts start to wear down over time.