Weird problem on every morning
 

Hello All,

Everyday in the morning, I switch the Engine on and put the gear in drive. Once the car starts moving and reaches the 2000 RPM, it drops to 1000 RPM immediately, as if I took my leg off the throttle pedal.

This happens only the 2nd gear or 3rd (Car is always on "C" mode). Once the car is driven/warmed for 5-10 mins it never happens.

I've done a quick test through Star SDS, it showed that the "B28" Pressure sensor is stored (Code: P2007-008).

Removed the sensor (A004 153 33 28), replaced it with the new one which is (A006 153 98 28). However, the problem still exists.

At this moment I don't really know what is cause of the problem. Hope you guys help me sort it out.

Thanks
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It sounds like you're describing the TCC solenoid issue. When the car is cold it starts out in 1st gear even in C mode, the TCC solenoid engages abruptly and only when cold. Once warmed up this goes away.

https://mbworld.org/forums/c32-amg-c...em-solved.html

Yep I second the TCC. Replace it along with plug connector and conductor plate, filter and new ATF and you should be good as new.

Alright then, I'll have to change it sometime .
Is it fine if I drive the car like that for a while ?

​​​​​​The thing is, its just a matter of weeks and the temperatures here is going to skyrocket again, so the issue won't be happening.

I read through that thread up into the 70's and one thing I didn't see... shouldn't a new conductor plate come with all the solenoids? I didn't realize you had to, or could replace them separately.

Solenoids are all separate, the conductor plate is just what supplies them with power. Solenoid failure is rare, especially shift solenoids, but for about $60 the TCC solenoid is a no brainer while you're in there.

I assume this solenoid is the most prone to failure being for the torque converter?

https://cimg9.ibsrv.net/gimg/www.mbw...a81a1847f6.jpg

B28 Pressure sensor error still exists, with 2 more errors.

Any ideas ?
Could it be the installed item is wrong part number ?

Well, I believe i got the infamous hiccup issue that usually happens on larger throttle bodies, although my car is stock.

It usually happens after a highway drive, once I slow down, the car starts to shake/surges.
Works fine after a restart ...

I'd check all vacuum connectors near the back of the supercharger, especially since you probably had some stretched to get to that darn MAP sensor (ask me how I know).

There's the brake booster plug/plunger and then a metal pipe underneath that, both on the drivers side, that are prone to leaks as well.

My hiccup has remained but I finally got a code for the bypass actuator motor, which greatly explains a loss in power between shifts and at random times when it should be closed but isn't.

Just pulled the supercharger tonight, what a chore, hopefully back together soon...

This. There is a vacuum line that attaches to the back of the supercharger on the driver's side (if you have a LHD car). I had this issue too after redoing my valve cover gaskets and I didn't put the metal part of the line back in correctly, it felt like it was in place but was not. Remove the driver's side surge tank and use a handheld mirror to get a better view of the grommet.

They are all connected ...