redant1

I posted on this issue before and it was suggested I change the transmission electronic connector. Since I was going to be under the car I decided to also change the conductor plate and fluid filter. I did that this weekend and the car drove ...... for about 2 miles. It then went into limp mode and then the transmission did not engage. I can put the shift lever into drive and reverse but the car won't move. I can put it in park and the tranny will lock. If I put it in neutral it will go into neutral. There is no check engine light. One other thing, the battery had been dead for a long time si I installed a new one.

I am at a loss and am wondering if my shift solenoids may be bad. Are there any other sensors that may cause this?

Thanks in advance for any help.

redant1

Since I've not gotten any response, does anybody have any suggestions as to where I may be able to get an answer? I have a TCU and will replace that this weekend.

dzmitry

I'd recommend to get the car diagnosed first, ideally you need someone with MB Star, you even buy "icarsoft mb ii" it's very useful tool.

scarlettdave

Agreed, get yourself an iCrsoft MB scan tool and stop spending money on parts you may not need

redant1

I bought the iCarsoft tool and found I cannot connect to the Engine Control Unit. Where on the car can I find that unit? I'd like to check the connections.

I checked online and found location for a W208 but not my W209.

dzmitry

It doesn't sound right. The car wouldn't start if there is a problem with ECU. Were you able to check TCU for errors ?

Just in case the ECU located under the hood on driver's side close to windshield.

dzmitry

BTW you can also check and clean TCU connectors. It's located under passenger's footwell. Usually when transmission connector leaks (they always do) transmission oil gets to TCU by wires (most likely by wires isolation). It sounds fantastic but it's true When I was removing mine foam which seats between TCU and carpet was soaking wet with transmission oil.

redant1

You are right the ECU is working and detected (user error). The TCU has no faults but I did manage to view the live data on the TCU. More specifically I viewed the transmission selected, target and actual gear selections.

When I shift the car from P to R I get: Selected = R, Target = R1 and Actual = P.

When I shift the car from R to N I get: Selected = N, Target = N and Actual = N.

When I shiftI the car from N to D I get: Selected = D, Target = D1 and actual = N.

What could cause this?

One thing to note, when you first turn on the car it will engage in R and D for about a minute or so. It then reverts to the above mentioned operation.

dzmitry

Here is an idea: it might be that rubber bushing with connects Shifter to the transmission shifting rod popped (or worned out ) and that causing the shifter not to move the shifting rod far enough (basically it created giant backlash).
On the picture #1 - shifting rod, #2 the bushing

dzmitry

And yeah you see different "actual" and "selected" values because TCU reads them from both Shifter module and Conductor plate.

redant1

I forgot to mention that I recently changed the conductor plate for the same symptoms. It drove for about 15 minutes and then reverted to the same behavior. Could it have been a bad conductor plate or something is shorting it out?

scarlettdave

Agreed, it sounds like a mechanical linkage problem, not something inside the transmission.

redant1

Update: I checked the bushing and it was missing. Part came in this week and I installed it today. No change in car mis-function.

Grasping at straws here but I'm going to order the shift solenoids and a new conductor plate. Hope to do the work next week.

redant1

One other thing I just noticed. I scanned the ECU and under the 'Drive Authorization' I noticed that the 'Immobilizer is Activated' status is shown.

Could this force the transmission to neutral or park only? Weird thing is that once all is cooled off it will work for a little while then revert back.