So I bought the nicest W220 S500 (2001) I could find and flew in to pick it up. All was well. The car drove great; there were no issues. When I went to drive away (long road trip, crossing many states), I plugged a usb adapter into the front cigarette lighter socket, plugged in my iphone to charge it.

Apparently, that was a big mistake, as my gas pedal from then forward had huge "hesitateion" in the low-end, basically waiting a bit and thinking about going before it finally took off, gradually, even if it was floored. This was the case even at speed for passing etc. Very strange. Occasionally, I'd restart the car (after gassing up, etc.) and it would be working properly again... but never for very long. It's like when you have a carbureted car that's not set up properly so it nearly stalls from a stop, but there's no stalling, just dumb inactivity and then a very gradual acceleration.

Upon returning home, I went to my very skilled Benz guy with the MBZ super-diagnostic computer, and we determined the gas pedal sensor was shot, and thus the pedal needed replacement, which we did with a new OEM pedal assembly. The car's seller had never noticed this odd pedal behavior, by the way, so it was new shortly after my drive-off. Anyway, got the new pedal and everything has been hunky-dory for the past week that I haven't heavily driven the car.

Until today, when my dumb *** drove it around a bit to do some errands, and then because my phone was dying, I pulled out the cable and adapter, and plugged it into the cigarette lighter again to charge. And wouldn't you know it? The damned (NEW) gas pedal was back to that ****e hesitation behavior again.

Is the link between the cigarette lighter and shorting out / blowing up the gas pedal a known fault in these cars? Of all the bizarre relationships, the lighter socket and gas pedal would never have occurred to me to put those two together.

If anyone's experienced something similar, please let me know. Looks like I'm getting another goddam pedal on Wednesday, and will not be able to charge the phone on a planned cross-country trip next weekend. This ought to be fun.....

 

The accelerator pedal is a common failure item

have never heard of using the lighter causing its failure though .

I would say you can try the lighter in the rear but don’t want to risk it ...you can buy a $30 battery power bank on Amazon strong enough to charge your phone 20 times .

don’t use your lighter !

 

Exactly where I was going!