Had my 2004 M6 in for oil change last Friday. Drove it rest of Fri and again on Sun morning. Tried to start on Sun afternoon and NOTHING - not even a click.

No interior lights, so assumed I ran down battery. Opened hood to jump start and noticed + terminal loose and hold-down unbolted. I'm guessing the Quick Lube tech checked the battery level and forgot to tighten (or pissed I didn't accept upsell pitch on radiator and trans fluid flush/fill (since I only have 19000 miles on car) and intentionally loosened).

Anyway, won't crank even with jump. Is it possible for key to get "locked out" and require reprogramming? Remotes still work, but key icon on dash continues to flash after locked and armed.

It's now at dealer, so I will get some info soon.

Thanks,
Dan

 

Totally disconnect the battery and reconnect. It should reset the car (In theory)

Was it loose enough that your battery could bounce? It could have grounded against the hood and popped a fuse.

 

Thanks for reply.

Car had to be towed to dealer and they are diagnosing. It is a mystery to them, apparently whole PCM is whacked. No fuses blew, which they are confused and concerned about.

I drove the car about 5 times (~30 miles) subsequent to oil change before it died.. I found the hold down threaded rod in the engine bay; maybe it arched? Very strange.

 

Turns out that battery had a short and was down to 5 cells or 10V. Tho lights and radio worked with <12V, the PCM needs 12+. Replaced the battery - prorated under warranty - and I got car back for $75.

This was my first experience with Mazda Roadside Assistance and dealer (Gaithersburg Mazda). Both outstanding!