Well one thing is clear you will not be fixing it in the parking lot ....if you will be attempting a fix get it towed home ... as a starting point...remove the rcm and check the solder joints this might be as simple as reflowing the joints.....look this up on this forum lots of info as to what to look for and what to do ...please ...l repeat dont tow it to a dealer unless you got money to burn ..... also start with the basics.....grounds ...... good battery etc ...lots of info here on line ....up date your post ...