2009 B200 A/T Intermittent Loss of Power RESOVLED
 

Hi forum

My 2009 B200 A/T is currently giving me issues - I'm hoping someone on the forum can shed some light.
The car will just lose all power while on the road for a couple of seconds (while accelerating), then when it regains power, it doesn't automatically shift gears to higher gears. That is, it stays in what seems to be first gear and won't allow me to manually change gears either.
This will happen until I turn the ignition off and back on - the behavior doesn't happen again until I park, say, overnight.

I have almost been involved in two major accidents as a result of this.
Can anyone please shed some light as to what may be wrong with the car?

It sounds like that could be a valve body. Pretty common issue.

This is to anyone who's had a similar problem:

• I took my car to Mercedes Northcliff, Johannesburg who charged me 1100 ZAR ~ $80 to run a diagnostic on my car (I would later discover that I could have spent a similar amount on my own device to read the error codes on the electronic modules on Amazon -
  Amazon
  Amazon
  )
  • Mercedes told I had transmission problems and they'd have to replace the valve body for 37000 ZAR ~ $2800. This is something I could not afford as I just bought the car for 100000 ZAR ~ $7500
• I then found a gentleman on Gumtree that would repair my transmission for 7500 ZAR ~ $560.
• He scanned the car for error codes and found that the sensors on the conductor plate were faulty.
  • he replaced them but the car still had problems
• He then suggested I replace the entire conductor plate and have it programmed with my VIN number. I ordered my conductor plate from shenghaiauto on eBay which cost me around 8500 ZAR ~ $635 including shipping to Johannesburg, South Africa (risky, I know). Be sure to supply the seller with your vehicle's VIN number. https://www.ebay.com/itm/722-8-TCU-C...7:pf:0&vxp=mtr
• After replacing the conductor plate, the car would start off ok for ~30 mins, then STILL go into 'limp mode'
• The car is now fine after the gentleman came through with his diagnostic device and cleared all error codes from the transmission control module's (TCM) memory
  • it seems like this was the missing puzzle piece in the repair - make sure to have this done after all your repairs are completed otherwise your TCM will still think there's a problem, even when repairs are complete

According to the gentleman, it is very unlikely that your transmission problems are as a result of a mechanical failure, so always start with your electronics before being convinced to change your entire gearbox.

Surprisingly, my woes with my transmission began when I had a major service done on the vehicle where I replaced the transmission oil. Go figure.

Good luck with your vehicle

Replaced the conductor plate and everything is now peachy