My 2004 TL has a complete electrical shutdown while driving. The electrical system will completely shutdown intermittently for ~1 to 2 seconds. Occasionally it will shutdown for a longer period and I have reset the clock and enter the security code to get the radio going again. It acts like there is a master switch of some sort that is disconnecting the battery. I only occurs on a hot day when the air conditioning is running hard. It most often occurs when shutting off the engine after the drive. I notice the shutdown because the doors won't automatically unlock as they normally do and the windows cannot be raised or lowered until whatever is going on has reset.

 

seem like you have a short some where. have you done anything wiring lately or in the past year?

 

Check for moisture in the PCM/ECU on the transmission tunnel behind the radio stack.

Also see if water from the A/C condenser is draining properly onto the ground near the right front tire.

G/L.

 

Interesting.

 

Try a new battery.

 

I do have an Ipod adapter that I installed a couple of years ago. Does the electrical system have a master relay that can reset the entire electrical system? I will look into the AC condensation idea. Thanks for the help.

 

Some members here had problems with their iSimples/iPod adapters, but those problems just deactivated the audio system, not any other electronics. Those problems were resolved by disconnecting and reconnecting the adapters.

Your combo of symptoms sound much more like a bad PCM/ECU.
There have been several cases where techs pushed bolts into the A/C drain tube to stop the condensation from dripping on them while they were changing oil or otherwise working under the car, resulting in the condensation backing up in the drain tube and onto the ECU. You can find a couple of threads here on that as well as some threads where the sunroof drains clogged and let water drop onto the ECU (which is near the firewall where all drain tubes traverse), resulting in symptoms like those you're experiencing.

You might also check the battery condition and battery cables for tightness-- the positive clamp tends to corrode and negative clamp often loosens up.
IIRC, other members here had systemic electronic glitches with bad batteries or loose battery cables, but not while the car was moving.

 

Hmmm I got the same problem. and I thought I was the only one

 

I'm checking the ac drain now