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2005 E320 CDI with inline 6, with 5 spd 722.6 transmission.
Items done to car include:
-Changed transmission fluid / filter, (Fuchs ATF4134), the level is perfect after checking numerous times with car in Reverse or Drive, E brake on, and hydraulic fluid temp of 80C.
Note that this trans fluid change was about 3.75 liters new fluid, not a complete 8 liter change.
-Added a new conductor plate, and new connector with new O-rings, and cleaned male connector plug with electrical contact cleaner.
-Removed and disassembled the valve body and reassembled after a good cleaning. No excess slop in any of the valve piston to bore clearances. I am 100% sure of correct re-assembly, as I took a ton of pictures during disassembly.
-Checked all shift solenoids with multi-meter (all checked out within spec), and replaced all solenoid O-rings with new. Didn't switch positions for the similar shift solenoids.
-Installed new rear left and right ABS magnetic rings, the old ones were shot, After install and test drive, MB2 scanner tells me that speed sensors on all 4 wheels are matching)
-New brake pads rear and front with new wear sensors.
-No CEL on dash.
-Removed the TCM from front passenger footwell, to see if any transmission fluid had crept into the TCM module from prior to my changing out the connector and O rings.
Also to inspect the circuit board and clean it with electrical contact cleaner.
There is some slight damage in the TCM, it looks like something has damaged the Circuit Board, There is no other visible damage evident,
Very unsure if this damage is enough to cause my issue.
Here is my issue,
When shifting from P-R, or P-D, or R-D, or D-R, or from N-P, N-R, N-D, the engagement into gear is very slow. It does go into gear eventually, 2-10 seconds, although never harsh.
When starting off with engine just warming up, the transmission will shift through all gears perfectly, I can see the gear changes on the Scanner as its shifting.
After about 5 minutes of driving, and transmission fluid is warming up, and with MB2 scanner hooked up, I get an implausible signal on target and actual gear. (Car is in drive)
I get a code P2561,(The gear is implausible or the transmission is slipping.(2nd gear).
I don't get a CEL on the dash strangely enough, only stored code in TCM.
There is no slipping of the gears, the engine does not rev beyond speed of car.
Transmission oil temperature at 60 degrees.
The status of shift valves is not present.
Note that before the code is thrown I can see the status of 3-4 shift point, never 1-2, 2-3, or 4-5.
Seems to be stuck in 3rd gear, it will not shift up or down from 3rd gear. Is the car in limp mode? Still no CEL on dash panel.
After short time (maybe a minute) of driving the P2561 code is back, and target and actual gear again shows implausible.
So, a few questions to anyone who might have gone through this frustrating exercise.
1) When I reinstalled the valve body, the shifter was in Park, and not in Neutral.
Does the shifter position matter when hooking up the shifter arm in the valve body?
2) Is my TCM kaput based on the above circuit board damage as shown in the picture?
3) Does the TCM need a simple reprogramming with Mercedes Star?
Remember that 2005 / 06 with inline 6 diesel, that TCM module is separate from transmission valve body, (don't think it is coded to the vehicle as in later years), located in passenger side footwell.
4) Does the P2651 code point to the TCM not being able to assist the shifting of the gears.
5) Does the P2561 code point to some hardware within my transmission that needs replacing or rebuild? If so, what needs rebuilding?
Figured it's worth knowing, but were you checking transmission fluid levels while the car is IN GEAR (drive or reverse)? When checking fluid levels, ideally you want it extremely warmed up and in gear.
Also, when you replaced the conductor plate, did you notice metal shavings built up around the speed sensor? My E55 AMG had these codes, and I discovered a TON of metal shavings around my speed sensor - disrupting the conductor plates ability to detect, effectively disengaging the transmission while in gear.
Yes, the transmission fluid level was checked with the car in gear, while monitoring the fluid temp through the MB2 scanner, it was warmed up to exactly 80 C.
There were no metal shavings around the conductor plate speed sensors when I took it apart.
There was only extremely fine grey material which apparently is normal.
The trans fluid was dark, so it was definitely time for a change.
I'm going to remove the pan, valve body with conductor plate just to have a look and rule out any conductor plate or reassembly issues.
I will also do another 3 liter new trans fluid addition.
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