xavega505

hey guys I'm new here since this is my first Mercedes Benz and I've had it for close to a year now i love the car it treats me good and docent break on me but something feels weird at first i though it was a transmission problem but since then i went to the mercedes benz dealer and asked to diagnose my car so they spent 2 hours changed me 150$ and couldn't find nothing wrong it then the mechanic starts telling me that he would need another 2 hours to try to find the problem and my cost would go from 150$ to 350$ and he thinks that i have a problem with my engine I'm like i don't think so because i have a independent shop in my area that I've taken all my cars to and i had quite a bit of them plus they are good friends of my fathers we do own our own body shop and they do all of out mechanical work the german cars and they specialize with mercedes benz they told me my engine and absolutely fine and there is nothing wrong it it that is where i do all my maintenance but besides all that at the dealers they gave me a print out of all the codes that been logged in my system over a long period of time and a lot of them say that (The Supply Voltage of the Control Unit is too low)(under voltage) and i cant figure out the problem and the main thing that i wanted to point out at the beginning that every-time i floor the car it feels like its chocking until it reaches 4000 rpm and then it start pulling fine if anyone ever had something like this going on please any advice about what to repair would be greatly appreciated !!!

Fabio D

MMmmmmm you replace your MAF sensor anytime? and, please, be more specific in the faulty. What do you feel, the car starts fine when cold or fail more when is cold in the morning tell us a little better whats the problem

Fabio Daniel

xavega505

simply put the car runs fine and drives fine but when it comes time to floor it it struggles untill 4k RPM and then starts pulling fine but from 1-4k rpm it feels like it wants go but it wont go any faster untill it reaches 4k rpm then it pulls really nice like if i want to spin my wheels even on the wet road it would do like half a spin and rpm's would go up with no kick feels like it only produces a good push after 4k rpms before it wouldnt speed up at all ! ill post some pics in a second of my diagnostics from the dealer gave me !

xavega505

xavega505

a lot of stuff there is under voltage im not sure if its related to the way the car runs or not tho !

xavega505

ohh yea and one other thing i had i was coming back home one day and was driving up the hill so i decided to push it a little so i pressed lightly on the pedal and around 2-3k rpm the car started to shake a little like it was stallin and my check engine went up and after a day or 2 it went back off and never came back on im just trying to remember everything that happend when i was driving it hope it helps with more info !

Nocturnal-G

Clean your MAF, check the fuel system, check all ground points, have the charging system load tested...

Seems like you have a variety of issues... I can't put my finger on it. How many miles do you have and what kind of maintenance have you done on it?

xavega505

i got this from another forums too

TPS sensor, in front of the master cylinder. The throttle cable hooks to it. Pull the plug and use electronic cleaner on the plug and the sensor. Let it dry befor you plug it back in. Used ones are $45 on ebay or a new one is $125 at autohaus. I bought my E55 4 weeks ago and it was doing the same thing. Fixed it about 10 days ago, very happy with it now.

xavega505

i have 111k miles on it ive done the tune up as soon as i got the car ive done regular oil changes changed bunch of stuff underneath the car control arms bushings ect its funny that the car dosent have any errors on the computer or check engine lights on or anything besides the power issue with it i have no other problems.....

Nocturnal-G

Do you have a multimeter?

xavega505

father works at a body shop i think they do have that !

Nocturnal-G

Have them check voltage... and if they can have it load tested.

xavega505

thank you will do

desired_speeds

the stored undervoltage codes is from when your battery died in the past. Have your codes cleared and run another quick test to determine if there are any current faults. Nothing in the photos you posted indicates a problem related to the car being underpowered.

xavega505

ah okie well do you think i should just change the MAF AND TPS Sensors and go from there if the problem persists ?

Neanicu888

What about that check engine light? I'd check that first...

Fabio D

Just change your MAF

Fabio Daniel

RobertG

Is the s/w switch selector next to the shifter ,on w or s?

Strigoi

nevermind

cudaized

Try this same scenario with the ESP in the OFF position. The large yellow triangle will display in the center of your instrument cluster.
It's just a test. See if the engine reves up better.

But I agree. A new MAF is probably in your future.

Fabio D

MAF, no more than this change it

Fabio Daniel