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I recently purchased a 2011 E350 4Matic. I bought it with transmission issues. I figured it was issues with the conductor plate so I sent that off and got repaired. After putting it back together the car drove fine for a couple days but now it’s stuck in 1st gear and shifting hard into drive/reverse.
My autel is reading codes for lost communication with the TCM. I can’t even get the TCM to communicate with the autel.
I read that it’s possible I need to get a new valve body? Does the valve body need to be coded to the TCM?
I recently purchased a 2011 E350 4Matic. I bought it with transmission issues. I figured it was issues with the conductor plate so I sent that off and got repaired. After putting it back together the car drove fine for a couple days but now it’s stuck in 1st gear and shifting hard into drive/reverse.
My autel is reading codes for lost communication with the TCM. I can’t even get the TCM to communicate with the autel.
I read that it’s possible I need to get a new valve body? Does the valve body need to be coded to the TCM?
I appreciate any feedback! Thanks!
You have a new conductor plate and tranny still unresponsive.
The TCM is attached to the conductor plate that manages the valve body solenoids that drive pressure pistons that shift clutches and brakes.
Do NOT assume this 100% internal condition of tranny. The CAN-C bus is shared by half-dozen other VIPS including unstable units.
Beware... you can replace all new $5,000. tranny and still get zero improvements....
You want to be absolutely sure ALL CAN-C modules are functional. Namely these:
ECU
TCU
ESP
ISM
CGW !!
There a fair chance your dealing with common voltage issues corrupting networking that disables TCM cooperation.
Scan the WHOLE chassis, pay attention to missing silent modules.
Thanks CaliBenz for the response! I am getting a fault code for no can bus for the steering module if I remember correctly. I recently dropped my subframe and I didn’t know about the connector from the rack to the chassis and when I dropped the sub frame the connector inside the wheel well broke and it would no longer snap together. Maybe the wiring inside the connector is messed up
Thanks CaliBenz for the response! I am getting a fault code for no can bus for the steering module if I remember correctly. I recently dropped my subframe and I didn’t know about the connector from the rack to the chassis and when I dropped the sub frame the connector inside the wheel well broke and it would no longer snap together. Maybe the wiring inside the connector is messed up
+1... you are on the right path with Steering Control Module ("SCM") issue even though I don't think SCM runs directly on CAN-C.
The scanner screen reports no ECU connection, that is DIRECTLY shared with your TCM.
This leads to solving why are all these modules unable to communicate well ??
One shorted module can bring down a whole network bus.
We know CAN-C (ECU + TCU) are disrupted in addition to SCM having issues.
With that said... go meet your "bus distribution bar" at both (L+ R) front doors thresholds.
Unplug each of the suspected modules until ... ECU or TCU come back alive.
What may cause that: rain soaked electronics.
Last edited by CaliBenzDriver; Sep 16, 2025 at 07:43 PM.
Hey CaliBenz thank you for the help on this so far. I have seen some of your other comments on the forums and it seems you are well versed and I do appreciate your help!
I do have an update. I went into both distribution boxes and had some success on the right side box. I started with the plugs closest to the front of the car. The second plug in allowed communication to be restored. I cleared all the codes and the trans shifted just fine through all the gears for about a day.
I took it through a car wash and as I sit in the wash I remember you saying water soaked electronics is most likely the cause.
I get home and turn the car off and then back on and it shifts into reverse hard so I knew communication with the TCM failed again.
I returned to the right side distribution box and unplugged the same plug that brought it back last time but no luck this time in restoring communication with the TCM. I then proceeded to unplug the remaining plugs in the box and none of them brought it back.
Any ideas on where to go from here? I will admit that knowledge on vehicle electrical systems is not a strong skill of mine so any input/knowledge is much appreciated.
Hey CaliBenz thank you for the help on this so far. I have seen some of your other comments on the forums and it seems you are well versed and I do appreciate your help!
I do have an update. I went into both distribution boxes and had some success on the right side box. I started with the plugs closest to the front of the car. The second plug in allowed communication to be restored. I cleared all the codes and the trans shifted just fine through all the gears for about a day.
I took it through a car wash and as I sit in the wash I remember you saying water soaked electronics is most likely the cause.
I get home and turn the car off and then back on and it shifts into reverse hard so I knew communication with the TCM failed again.
I returned to the right side distribution box and unplugged the same plug that brought it back last time but no luck this time in restoring communication with the TCM. I then proceeded to unplug the remaining plugs in the box and none of them brought it back.
Any ideas on where to go from here? I will admit that knowledge on vehicle electrical systems is not a strong skill of mine so any input/knowledge is much appreciated.
You know... unplugging CAN Members is not a lottery.
You need to know which plug is what module to understand what is helping or hurting your TCM.
Without that you can't progress down to that one bad line...
TCM shares its control bus with half a dozen of module. My go-to bad guy is the CGW-SAM or ISM because it's connections are really exposed.
> Try these steps:
-- Scan chassis to note faults + missing modules
-- Reboot the whole chassis by disconnecting all batteries power for 15mn.
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