TECH: SES light on... - The Unofficial BMW M5 Messageboard (m5board.com)

BlueBomber · 9th May 2002, 16:39

I noticed yesterday (5/8) that my SES light has come on. This is very strange since there are no noticable symptoms (power loss, funny sounds, etc.).

I suspect that it was because I did not screw on the gas cap until it clicked as I normally do. However, the last time I filled up the tank was on Monday (5/6). If the gas cap is not complete tight, does it take 2 days for the SES light to come on? Also, do I have to go to the dealership to have the SES light cleared or will it clear itself after the next fill-up?

Anyone experience something like this in the past? I plan on heading to the dealership tomorrow if the light has not cleared by then.

Thanks in advance!

CM5GO · 9th May 2002, 16:50

If your gas cap was not completely tightened, that was likely the cause.

It takes a couple of days for the computer to recalibrate and turn the light off. You do not need to go to the dealer to get it reset.

It took three days for mine to turn off. Dont worry it is just a measure for emissions and it will not affect the safety or running ability in any way.

If it does not go off in a couple of days, it may be something else so you should have it checked.

Hang in there for a couple of days and I suspect it will turn off.

BlueBomber · 9th May 2002, 17:29

Thanks for the reassurance. I'm not really worried since there are no noticable signs of problems.

I'll run to the gas station later tonight and hopefully it'll clear within the next few days.

Thanks again!

BostonRocket · 9th May 2002, 18:07

If after you have tightened the gas cap and the light returns, have the Techs check the pressure release valve on your gas tank. A faulty one will simulate a loose gas cap. A few of us on the board have had this problem.

'Rocket

BlueBomber · 9th May 2002, 18:20

Ahh... thanks for the tip Rocket!

Teutonaddict · 9th May 2002, 18:21

There are any one of a number of causes of the SES illumination. If you're not experiencing obvious symptoms of poor performance, I wouldn't worry just yet. As others have observed, it could be from the gas cap. But it could also come from a number of other triggers, such as slight impurities in fuel, a hung up sensor, blah, blah, blah.

I'd wait a few days, through multiple ignition cycles, and see if it goes away.

I've had this happen maybe half a dozen times in 37K miles, and each time it extinguished itself. One time, on my way to a DE at Roebling Road in Savannah, GA, the SES started flashing at me. It happened immediately following a fuel stop, but the cap was on tight.

I called three different dealerships that were en route to my destination to ask their advice. Amazingly (or not), they asked the same questions the moment I said "SES."
1) Did you check the gas cap?
2) Did you just add fuel?
3) Is the car showing any syptoms?
In the end, the all told me not to worry, even tho' none could explain why the SES light was flashing. As I recall, it went away with the next cycle of the ignition. Problem solved.

Good luck!
-Dave