Hi Guys,
I have a bmw 323 E90 and customer complaining of a repeated flat battery, have checked battery, charge rate and carried out a parasitic drain test. I'm showing a current draw of 250mA when vehicle has finally gone to sleep (this has taken approximately 30 mins). My question is what is an acceptable drain? Any help appreciated.
250 mA is too much. There are several methods to determine the faulty circuit, you can try fuses voltage drop test and why not, thermal imaging camera.
Hello,
Some faults in engine control module(like smart sensor,alternator,aux water pump-all share the same bus of data)?
I think a current consistently over 50 mA must be investigated.
Best regards
Thanks Guys. Unfortunately I don`t have a thermol imaging camera but that is a flash suggestion. I -believe that I am down to the fuse pulling or volt drop testing methods for the time being! I will be testing with the 50mA and less in mind.
Thanks again
So, I don't know about BMW's specifically, but I know that Fords made in the same time period needed to be at rest for at least 40 minutes before going to sleep. I also remember reading TSBs from other german automakers (maybe Audi?) that say to let the vehicle sit for at least 2 hours before doing a drain test.