SKY545

I appreciate everyone's comments...I'll post my solution early next week when I find out for sure what it is.

530la

i had the same thing pop up in my 2005 525i,,i took it to the dealer and it was caused by the thermostate they replace it. Then about a week 3 days later it came back on, i took it to the dealer again n they reset it and they said i also needed a new battery so i replace the batter for 495 wow they got me good, but the car seems to run better n i feel like the acceleration is smoother>

Bimmerchop69

So yesterday I reset the SES light after replacing the gas cap and so far I have not had the light turn on after 50 miles.

SKY545

That's expensive for a battery replacement! I had mine replaced last month and my dealership charged me $325 for parts and labor including the registration.

SKY545

How do you reset the SES light? Thx.

cooldns

I have 2005 545 (about 92,000 mi.) and I had the same problem!! Had the radiator expansion tank replaced and my independent mechanic recommended that I replace the thermostat. All that done and a couple of weeks later the "emissions" and "service engine soon" messages came on. Had the thermostat replaced again. Now the same "emissions" and "service engine soon" lights come on again about two months later. They find no fault and they reset it, and it cost me $282. for that. Now he tells me that if the fault code comes on again, then I need a new wiring harness for about $1,600. with labor. The car drives perfect with these codes on and I guess I should drive it for a while with these fault codes on until it starts running badly. Comments........ Thank you.

cooldns

I have 2005 545 (about 92,000 mi.) and I had the same problem!! Had the radiator expansion tank replaced and my independent mechanic recommended that I replace the thermostat. All that done and a couple of weeks later the "emissions" and "service engine soon" messages came on. Had the thermostat replaced again. Now the same "emissions" and "service engine soon" lights come on again about two months later. They find no fault and they reset it, and it cost me $282. for that. Now he tells me that if the fault code comes on again, then I need a new wiring harness for about $1,600. with labor. The car drives perfect with these codes on and I guess I should drive it for a while with these fault codes on until it starts running badly. Comments........ Thank you.

Bimmerchop69

New wiring harness. Wow I would get another opinion on that. If you have a SES light on then it has to have a code. I purchased a basic OBD2 reader from the autoparts store. I used it to read the code and then reset the code. A OBD2 scanner costs around $100 and if your dealer charged $282 then they are scamming you. Definitely go to another stealer.

SKY545

Just wanted to give an update on my situation. Last weekend, the Service Engine Soon light went away by it self after being on for a good four days. Not sure what the deal is with that, but I guess it works.

My car has been at the dealership for five days now and I have been told that I need to change the primary thermostat (no problem, covered by my third party warranty) but if the problem continues and I still get the Service Engine Soon light, then I would have to change the wiring harness which I was quoted for about $2k. Total rip off and I'd want a second opinion. The car drives just fine!

I've decided to just change the thermostat right now and see what happens...thankfully they gave me a 2011 328xi as a loaner. Should have my car back early next week...hopefully, the service advisor said he wanted to "check something" with the technician.

e6t.lab.rat

Hey guys, read through this thread/DIY I made last year for our 545's (pics on page 4 I believe). I found out later that there was a recall regarding this. My dealer at the time told me this is a common yet simple repair for our cars. Hope this helps.

https://5series.net/forums/topic/853...ssion-no-more/