Chasing codes 12 C300 4 Matic Sport
 

Howdy!,
I have the above American spec beauty and am chasing the source of ESP/ABS warning lights. car has 96K on it base model. Just addressed P1721, limp issue with a conductor plate overhaul and full fluids maintenance front o back on the car. Put about 50 miles on it , reset adaptation and no limp, or codes so feeling good about that. . Other than ordering a OEM brake light switch as a SWAG my I-carsoft MB2 is showing the following. 1) Under TCM menu No CAN message was received from control unit, N47-5 (ESP and BAS control module) and all the other related N47-5 modules. 2) this is the odd one:1425 (no alpha code) Found under engine/6 cylinder menu "Wheel speed signal is implausible".
My gut is telling me code two is causing the code one "reaction". Odd thing is at the component level I don't want to assume we are talking wheel..as in ABS. This code is under the engine menu. Was think crank/cam position sensor. Unfortunately I don't see anything online that is definitive for this make/year model.
I can clear it and on occasion it will be fine for a few miles but then pops up. Anyone help a brother out with some more detailed data? Thanks in advance, Matt

What does Google tell you? This is a common error code.

- confirm wheel and tire size and condition is correct including equal inflation pressure on all 4 tires

- confirm correct function of wheel speed sensors by swapping sensors between wheels or by swapping in a new sensor and seeing if the code goes away

- what mechanical maintenance has recently been done?

- after all of the above is done, including asking Google, ESP module may suspect.

Leftt front wheel sensor..:)
 

I was test driving it when I got your reply. It was indeed the left front wheel sensor. Nothing definitive hit when searching the web. I woke up this morning and decided to look at live data. Using my icarsoft MB 2 I went into the brake EBD menu and could see a lack of wheel signal when moving from the left front. Payed $110 at the Merc dealer for the darn sensor but I want to be done with the car...today...after spending a week plus doing the conductor plate, fluids front to back with the wheel ESP/ABS issue being the last. Cleared all the codes and just hammered in the new brakes. 60 Spirited miles later I think I am good for now. 96K
Thanks for the reply! Matt