Adding pin on ECM plug. Disconnect batteries first?

[Motorhead]

I bought the ECM pin to add on for the HIGH idle feature. I see alot of you guys have done it. Do I need to disconnect both batteries first or just unplug the "B" plug and insert the pin?

 

[jelag]

YES... . any mistake here can cause ECM damage... . disconnecting the battery is cheap insurance that you won't have any problems. .

 

[Motorhead]

Thanks... I figured that would be best but no one mentioned that they disconnected the batteries first.

 

[JCasper]

I disconnected my batteries and would suggest you do so also.