Throttle Positioning Sensor
 

Have a 1996 E 300 Mercedes Diesel. Had a problem with Glow Plugs and starting, a lot of smoke when starting. My mercedes mechanic in Florida told me to have them replaced if I stay late into Fall during cooler weather. Since weather has warmed starting is OK. Recently,this week engine light came on stayed on. Went to Advanced Auto and a free diagnosis and a code came and referred to the TPS. I called my mercedes diesel mechanic in Florida and he said not to worry. (I am presently here in Southern New England till late Fall.Will this hurt engine or make car fail? Does TPS regulate fuel consumption. Prior to this problem,all highway driving,car is getting between 35-38 mpg and city driving 27-27 mpg

tps is likely to inform the motor both fuel needs, and transmission needs.
in 96, I'm pretty sure fueling is still mechanical, so it'll only affect transmission shifting.

The throttle position sensor error code can have a multiple causes. There are a number of sensors that work in combination with one another which can cause this code besides the "throttle position sensor" itself. which is located adjacent to the firewall, drivers side.

There is a small black sensor connected to the intake manifold atop the driver side wheel well.

There are two other sensors located on the side of the air intake filter box. Both of these sensors have the same part number. One controls the resonance flaps, and the other controls the EGR valve.

On the underside of the intake manifold, there are two vacuum devices that control the resonance flaps.

All these sensors are all connected by small rubber vacuum lines, that can spring a leak and cause a code, so I would check those out the vacuum lines themselves first.

The second thing I would do is disconnect all the electrical plugs to each sensor one at a time, and spray each one with electric contact cleaner, and re-attach. Good luck!!