This comes directly from the "Gas tank content" thread, but it was sort of off topic, so I figured I'd start a new one...


"If you do the battery disconnect thing, I must stress you have to be very careful for if you do this wrong you can possibly do some electrical damage to the car's DME."


So, reading a lot of threads throughout Forums (here, rennlist, renntech, etc.) ^this^ is mentioned often. My question(s) is/are how or why? Is this some sort of "urban legend" ? Is there a specific "DO NOT DO THIS" procedure? Is the 996/911's electrical/electronic system so fragile and sensitive that it can't be jump started without causing damage? Could something as simple as disconnecting the battery really cause damage to the DME? What if the battery dies (as is so often the case) - which seems to be almost by design? There just seems to be a lot of confusion and or disinformation regarding this subject - hopefully these questions don't add to it...

 

Well here is what I know. When disconnecting the battery you must always disconnect the negative (-) lead first, then the positive (+) and reconnect in the reverse order. Otherwise you risk creating a short circuit which will/could damage the DME.


When I replaced my battery I took one extra step; and that was to cover the leads with a piece of rubber (old bike tube) to prevent any potential electrical accidents.

 

^+1^ Thanks. AFAIK this is SOP with any and all car batteries, so nothing specifically Porsche...