I was hoping someone might be able to help me out with an issue I am having with my 2004 Z4. On Saturday, the car was not starting for me so I did end up getting it jumped thinking that the battery was just low. I drove it around and came back home. The next day i went to start it and it was not working again. I tried jumping it, but that didn't seem to solve the issue this time. I did accidentally disconnect the negative connection on the battery when I went to jump it this time, as I found out that it was extremely loose.
It appears the car has gone into some sort of security mode where the car is not letting me start it using my key. The power top also seems to be locked. Does disconnecting the battery cause the vehicle to do some sort of reset? If so, does anyone have any suggestions as to how I can get the car to start again?
Thanks!
Try replacing the battery. It sounds like it's not worth a darn.
ASE and BMW Master Certified Technician
Thanks for the reply! I tested the battery and it appears to be fine. It was replaced in November of last year.
I know with the E36 models there is a fuse that can blow and cause this. It's right next to the battery. I haven't been able to find a schematic for the E85 to see if they also have one. With the cable extremely loose the surges could cause a fuse to blow.
You need to define "not starting".
- When you turn the key does it turn over but not fire? - That could be a myriad assortment of fuel or ignition issues.
- When you turn the key does it turn slowly or just click? - Your battery is weak/shot or your starter is going out.
- When you turn the key do you get all of the dash lights brightly but no response (clicks or otherwise) from the starter? If so...
...Your ignition switch has failed. If you try several times and it finally catches, this is probably the issue. Common with BMWs (and happened to mine).
...The starter has gone out completely.
...Your key battery is dead or has lost programming with your vehicle. Do you have a spare key to try?
Last edited by keeton; 04-25-2020 at 02:30 PM.
Did you load test the battery
Hey thanks for the reply. The third scenario you mentioned is what has been occurring. When I turn the key, I get all of the dash lights, headlights turn on but there is no response or clicking from the starter. I just had the EWS and starter replaced by BMW and am having the same issue. I will try several times and it won't turn over, but then i give it some time and it will fire right up. My key is brand new as of 2 weeks ago, genuine from BMW.
You would think that they would have checked the ignition switch, but the service department said that the car is not reading any codes at all, once my EWS was replaced.
Just to clarify a prior response that you replied to...
Brand new key does not negate the suggestion that you look at the ignition switch as a possible cause. If the ignition switch is the problem as was suggested ... new or old key does not make any difference.
So if you haven’t solved the issue as of yet... the replacement of the ignition switch is an inexpensive DIY according to posts.
Read these...
https://www.google.ca/search?q=z4+ig...&client=safari
Sent from my iPhone using Tapatalk
Now long ago did they do the work, if recently then they need to look at their work
Same thing happened to my z4 last year, it was starting fine then one day no start. I had it towed to a friend's shop. Next morning it started right up...brought it home. Since then it has been a hit and miss if it’ll start. Brought it to an independent BMW shop and after two days of diagnosis they said I needed a new DME. Had it replaced and car starts and drives great.
I was hoping it was the ignition switch, battery or starter...lucky me it had to be the DME.
Last edited by carlsson01; 06-17-2020 at 09:57 PM.
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