I have not had a chance to clean the underside of the X yet. Snowing like a son of a gun here. I will get under there one of these days with rags and de-greaser, especially if the light doesn't go out this week.
Thank you so much for the insight and help.

^^ forget it. Read the codes. I'd bet you a 6 pack of e-beers it is not oil on the outside of the car causing a CEL.

Read the code, WRITE IT DOWN, and reset it.

If the light goes out, the code will still be in memory...then the next time you have an issue you will not know which code caused it.

Read the code, report back.

A

Update:
With all the snow we have been having, I'm sure a lot of water had passed through the underside of the car. The 'check engine soon' light is now out :-)

1. The code is still there.
2. The light goes off when the fault is no longer present.
3. It wasn't water nor snow on the bottom of the car. If it were almost every car in america would have the light on all the time


It is funny how superstitious peoples seem to seize on unrelated events and attribute them to be causes of phenomena they cannot understand... like tribespeople.... It snows, the light came on...must be the snow. I changed the oil, light came on- must be oil change.

Carry on

A

You missed the first part of the story man. Light came on after power steering hose ruptured and sprayed fluid all over the bottom of the car. After replacing hose and fluid, started car and got the light. It was suggested that all that fluid got over some sensor(s) and caused triggered the fault. The snow simply cleaned off the oil, or heat burned it off, and now light is off (three days later).

So settle down...:nanana:

So got my X5 back from the dealer after three days in the service dept. They did take my concerns seriously to do more thorough diagnostics beyond the gas cap, apparently found some diagnostic faults and smoke test leak. They tried replacing one or two things including the sensor, before finding "fuel pump top cover melt through" and "fuel sender melt through", sealed up those leaky areas of the fuel tank. They said they were going to replace the fuel pump as well, but not sure if that was ultimately needed.

No that is not what happened. There are no sensors under the car that when oil is leaked onto them will cause the CEL.

Any transient CEL will clear in a few days if the fault doesn't recur... a loose gas cap is the classic.

But yeah, go with the snow washing off the sensor. Had you sacrificed a virgin it would have cleared faster.

:nanana:

:bustingup I guess none of the other mechanics on this website know what they are talking about, just you. By the way, this section of the forums are for help, not your rhetoric. Go to the politics part if you want to try and feel better about yourself.

Of these 4, it was the evaporative system causing the code in my 550i.
. It can be a faulty cap that isn't sealing.
. It can be a leak in the evaporative emissions control system
. It can be a fault in the air pump that creates pressure in the fuel tank and evaporative emissions control system
. It can be a sensor in that system.

"mechanics" ????? You are kidding me, right?

I see no mechanic posting in response to you theory. Most real mechanics skip thread like these in which people cast about trying to correlate at CEL (which can be set by 100 or so faults) with a possible cause... How about "bad gas"? Always a perennial favorite when a CEL occurs after a fill up.

Don't throw the baby out with the bath water: I can be acerbic and sarcastic, but you'll find 'correct' on occasion...

A