Unlpug ECU before diconnecting battery?

[m4rk]

Hi,

I usually unplug my ECU before disconnecting the battery and only reconnect the ECU after the battery is reconnected. There are usually some sparks involved when messing the battery connections and I was being cautious with the ECU. Is this necessary or not?

[That Daddy]

Its actually the correct procedure to disconnect the battery 1st before unplugging the ECU and be fast to connect the leads to not allow lessen the arcing effect

[m4rk]

Thanks, that will save a lot of wear and tear on the ECU connectors. I have had the battery on and off lately.

[fenderbender]

Alternative is to do what I always try to do - connect a 12v motorcycle or similar small lead acid battery across the terminals before removing any car battery. This keeps the power running to the parasite systems (clocks, radio, alarm, etc) and avoids all the tedious resetting of radio codes, etc