You replace the entire peddle: the "sensor" is the peddle. MB part # 170 300 01 04. Prices range from 240 at Mercedes, 169 at FCPeuro for new, to about $100 or less for used on ebay.

 

Is the throttle position sensor in the gas pedal. Are several on ebay. If you have an automagic it also has a kickdown switch. Are several threads on how to check. Note: service manual talks about a "upper nut". Is not there just one nut and can pull out. Upper connector is hard part. Automagic shown.

 

Padgett you are confusing people; " Even Torque Pro can read the throttle position sensor (main one at least)" is NOT the sensor associated with the P0123 code. The sensor you are referring as 5 at idle and 20 a WOT is snapped on to the side of the throttle body attached to the rear of the engine.
The Accelerator Pedal Position Sensor is the foot peddle in the driver compartment and associated with the P0123 code. TWO COMPLETELY DIFFERENT SENSORS doing different jobs. Mercedes part # 170 300 01 04 refers to the Accelerator Pedal Position Sensor.

 

Thank you for the clarification. Most cars make do with one Throttle Position Sensor, the Crossfire has three ? Two in the pedal and one is on the engine end of the fly by wire ?
Do know when I had the bad pedal in and had error P0122, the Torque Pro TPS reading was 0-2 and when working properly was 7-20 so regardless of what was being read it was indicative of the problem.
Guess I am always learning something.

 

I have spent a couple of hours trying to get a clear answer, here and online about this, without any result . . . Does anyone know the difference between those two different numbers for the accelerator pedal . . . Excluding the price difference

A 170 300 01 04 Mercedes Accelerator Pedal Genuine Mercedes 170-300-01-04 170 300 01 04 170.300.01.04 1703000104 | Pelican Parts

A 170 300 02 04 Mercedes Accelerator Pedal Genuine Mercedes 170-300-02-04 1703000204 170 300 02 04 170.300.02.04 | Pelican Parts

Daniel

 

Apparently, the 01-04 fits our cars and the 02-04 apparently doesn't. What other details would we care about? Your links did not show prices to me.

But I did find this:
https://www.pelicanparts.com/catalog...PPEDAL_pg1.htm

I believe that is the compatible part for our cars.

 

Followed this thread to fix Accelerator Position sensor, bought the replacement shown below. When removing original pedal, I noticed a second wire that goes in back and connects just below full throttle switch. The new one I purchased does not have a connector there. Is this something that comes out of the old pedal and fits into the new one?

The new APS

No connector on this one

 

I see now that I have bought the wrong part.

 

Texas Thunderman
The pedal part# you purchased begins with A230, the part you are looking for is A170. The 170 is the number assigned to the SLK model prior to 2005 and used in the Crossfires. MB apparently used the A230 in another model and changed the configuration and will not work in the Crossfire.
Time to return the part and buy the correct one A170 300 01 04....
Regards,
Dennis
DTMenace