How To Guide Fried ECU?

[Towerman]

Hi, I recently bought a 2006 Z4 2.0 sport roadster. Rarely using it, inevitably, my battery went flat. Having re-charged it, I found that the heater fan would only run at slow speed. Thinking that it was a simple matter of resetting this through the OBD, I purchased a Bcables.com cable and associated software online and set about trying to cancel the code. The instructions were scant and there's no back up support from the sellers. I now find that I can't turn on my ignition or start the car, even although there is plenty of power in the battery. I fear that I've lost everything on my ECU or I perhaps I need to re-initialise the ECU. Would I be able to achieve this by disconnecting my battery and re-connecting it again or would that then cause a permanent loss of all electronic settings and information. Jeez, I wish I had just taken it to a dealer!!! Suggestions please, yours in desperation!!!

 

[t-tony]

It had gone into "Transport mode" which is quite common. Hard to know what has happened since. It cannot hurt disconnecting the battery as I don't see how it could make things any worse. Where are you located?

Tony.

 

[Towerman]

Thanks Tony. I'm located in Falkirk, Central Scotland. I put a test meter across the battery when I got home tonight and found that it was only reading 6.6 volts, contrary to my belief that it was fully charged last week and Kwik-Fit testing it and telling me that it was okay. Not sure how it got discharged again but I'll check the state of play tomorrow once it's sufficiently charged - fingers crossed it'll burst into life!! Hoping that that will work but I'll probably still have to reset the transport mode to get the heater fan and A/C functioning again. Do you know if these off the shelf OBD readers such as sold in Halfords can reset that status or will it have to be done by a BMW dealer?

 

[t-tony]

No, these small code readers won't help. I had to take my mates Z4 I to where I used to work to get it reset. Apparently the transport mode was used to preserve the battery in transit and was reset on PDI. Some people have had this reset at the dealers for free so may be worth a call mate. Hope you get it sorted ok.

Tony.

 

[Mint]

Batteries seem to die almost overnight these days. I can remember the days when a battery gave you quite a bit of time warning you that it was getting towards the end of its life. You may find a new battery solves your problem.