As with many other folks, I was privileged to endure the recent ice storm in DFW [aka, Mother Earth presents Texans on Ice]. My 08' R56 lives outside, and it stayed put for several days while the roads thawed. Several days into the ice, I started it to help thaw things out. I fully expected my battery to be somewhat weak. For some reason, my car has never played nice when the temperature drops below freezing [this battery is ~24 months old and the previous battery had the same symptom]. The car fired up despite the weak battery. However, it immediately threw a CEL. It took awhile to warm up and settle down, but it appears to run fine otherwise.

Would a weak battery throw a CEL?

I have yet to run the codes on it to see if anything registered.

 

Read the OBD codes... no codes on the reader. Tomorrow I'll go through the process of pulling the factory codes from using the tach method. FAIL!