How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Ron Your Own Question
Ron, ASE Certified Technician
Category: BMW
Satisfied Customers: 36047
Experience:  34 years Fixing Cars and Trucks
Type Your BMW Question Here...
Ron is online now
A new question is answered every 9 seconds

2005 745 turn car off, will not start unless you jump it.

Customer Question

2005 745 turn car off, will not start unless you jump it. New battery from dealership. Dealership techs baffled. Module? Any ideas?
Submitted: 2 years ago.
Category: BMW
Expert:  Ron replied 2 years ago.
Hello, my name is ***** ***** I am a professional here at Just Answer. I have noticed that your question was not getting a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.
If the only way it will start is with having to jump the system then you are likely dealing with a drain on the system drawing the battery down providing the alternator is working properly. Has the dealer performed a draw test to see if then can isolate the drain?
Customer: replied 2 years ago.
I have a pile of receipts from the dealership now totalling over 10k for various problems. I see things like checked electrical system, replaced battery etc. None specifically addressing the draw. My brother in law got tired of the dealer (3hrs away) and brought it to me. I am a small shop mechanic but he is willing to get me what I need to get this fixed. I isolated the key at least 100 ft from car and after 2 days battery is reading 11.6 just checking with multi meter
Expert:  Ron replied 2 years ago.

I have enclosed the BMW battery draw steps in the link below which should help you isolate the problem.

Copy and paste the link to your browser to open and view it.

Customer: replied 2 years ago.
I will try this if it does not figure something out for me I will call it would be after 5 o'clock central time
Expert:  Ron replied 2 years ago.

Run through the steps and see if you can find the draw. Chasing them can be a real pain in the rear but usually they can be found if you stay after it.

Customer: replied 2 years ago.
I will stay after it I am technically on vacation I have two small kids starting school tomorrow and just got one off to college kind of doing this as a side project for my brother-in-law but I will get it done much appreciated I will let you know the results
Expert:  Ron replied 2 years ago.

Okay , good luck on the hunt and also make sure you enjoy the vacation as well.

Customer: replied 2 years ago.
Just pulled codes on the car while working on the battery draw. Runs rough.P1720
Expert:  Ron replied 2 years ago.
See the complete list of the codes in the file below, none of these codes should cause the battery to die on you. The P0300 is a random misfire code and the P0305 indicates its on the #5 cylinder. Copy the link below to your browser to open and review the other two codes.