What is that under the accelerator pedal? It has wires going to it....
Ken

 

which vehicle are u talking about. some have the kickdown switch under the pedal, when u stomp on the gas and hit the switch it shifts the transmission down and allows u to reach higher rpms when accelerating fast.

 

I have a 190D. I think that is what it is and what it's called. When I floor it, it doesn't downshift, therefore, can I assume this part is bad? Any way to test it?
Thanks,
Ken

 

Under the accelerator pedal, there's also the jump point for the battery where the positive 10 MM cable from the rear of the car is connected.

 

If your flooring it and the tranny is not down shifting it could be as simple as the kick down switch is out of position. Mine was on my 79 450SLC it had come loose and sunk into the floor, that was a easy fix, or it could be a loose wire either at the switch or at the tranny connections. These switches are fairly bullet proof, I haven't seen one fail because it was bad, but I have had my personal experience, and doing some research when I had problems with mine found that loose wires or switch is most likely the problem. According to the design of the accelerator pedal you might have to take if off to get to the switch.

Also check to see if the carpet hasn't buried the switch, I've heard so folks have had this problem also, the carpet after years of use, the hole for the switch works itself up and around the switch. Take a long screw driver and push the carpet back down.

Constant downshifting the tranny with the kickdown switch will quickly ruin a tranny. Your tranny should downshift to the next lower gear when you push the pedal down about half way. If this is not the case then a accelerator linkage adjustment is in order. The kickdown according to what speed you driving can shift the tranny down to first or second gear. Over 20MPH 2nd gear is the best you'll get, below 20MPH 1st gear should engage.