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I have a 2007 e350 went out wouldn't start one day outta nowhere found that if you jump the starter relay fires right up with no problem at all . Did some looking and found the lost communication with tcu so ended up replacing tcu , conductor plate ,did solenoids while I was in there , changed to new connector also put new ground strap on trans also . Gear indicator on dash doesn't show up still and doesn't start without jumping relay once you jump the relay it runs and drives with all gears .
I have a 2007 e350 went out wouldn't start one day outta nowhere found that if you jump the starter relay fires right up with no problem at all . Did some looking and found the lost communication with tcu so ended up replacing tcu ,
conductor plate ,
did solenoids while I was in there ,
changed to new connector also put
new ground strap on trans also .
Gear indicator on dash doesn't show up still and doesn't start without jumping relay once you jump the relay it runs and drives with all gears .
You're saying you did all that good work without a change in the original problem? The positive side is this maintenance is done.
You don't say what current/stored fault codes are there.
I think you may be dealing with a worned out ESL actuator or the amazing Gear Shift module aka. the ISM: Intelligent Servo Module.
They are both involved in the drive authorization that is currently working against you.
Last edited by CaliBenzDriver; 04-16-2023 at 08:05 PM.
You're saying you did all that good work without a change in the original problem? The positive side is this maintenance is done.
You don't say what current/stored fault codes are there.
I think you may be dealing with a worned out ESL actuator or the amazing Gear Shift module aka. the ISM: Intelligent Servo Module.
They both involved in the drive authorization that is currently working against you.
The car does currently tell me ABS ESP inactive and the esp light was on prior to the problem currently there are no codes because I did delete them when I just tried the jump process and took it around block to see if it was locked in limp mode which is not so had all the gears the codes were the lost communication to tcu and something about a front axle speed sensor (which I didn't think would affect this ) also the tcu was a good used unit with all matching numbers on everything so was told I wouldn't have to program to vehicle
You've got to figure if ABS is the victim or the culprit here. Tranny does need wheel speed to shift!
Any faults back yet after clearing report??
Any missing/silent module?
Any obvious sign of bathing in the F-SAM tub?
Can you interact with engine ECU, Steering SCM module ?
Do you have a way of scoping your CAN-C??
I just took it for a ride to get some codes back and I got u0101 p2158 and p0715 (jumped relay to start then used the button on back of shifter to put in gear ran through all the gears until 3/4 way back and then went into limp mode) p.s. when it was driving the gear indicator was on dash soon as stop it's gone also I don't know much about the can system still learning that aspect
CAN is a network data bus, in some respects similar to the Ethernet used to connect computer office networks. Physically, CAN is a twisted pair with a differential signal. each CU on a CAN has an address, and broadcasts messages, only one node can send a message at the same time on a given CAN. a message can be something like, 'front wheel sensor says 55 MPH', or 'engine temperature is 90C', or whatever.
the W212 has like 5 different CANbus, all tied together at a central gateway module (part of the front SAM) that acts like a router. there's around 25 modules in htese cars that talk over CAN, and its god awful complicated. All it takes is one bad module spewing out garbage on its CAN interface to jam the communications on the whole car.
this shows how some of the CAN are connected.
MOST is another entirely different thing, its fiber optic multi-media, used to connect the COMAND radio+stereo to the amplifiers
LIN is a low speed bus used for things like connecting a door module (windows, locks, mood lighting) to the chassis module, or the headlights, etc
I just took it for a ride to get some codes back and I got u0101 p2158 and p0715 (jumped relay to start then used the button on back of shifter to put in gear ran through all the gears until 3/4 way back and then went into limp mode) p.s. when it was driving the gear indicator was on dash soon as stop it's gone also I don't know much about the can system still learning that aspect
P2158 is ECU complaining about lack of wheel speed (limp mode!)
P0715 is the TCU complaining about speed sensor (limp mode!)
U0101 is the TCU complaining about bad Coms reporting that through Coms (it's on multiple CAN!)
Go ahead and disconnect the CAN Distribution to ESP(ABS) and then stay parked during work (ie. do not test drive!)
You want to assess if this eliminates disruption to improve your CAN-C usability.
Obviously all the "missing" ABS sensor data will trigger related faults all over the place but then you'll want to confirm that Coms should be back in service if indeed ABS was the bad guy... else repeat with next CAN-C module except ECU/TCU that are assumed good.
We got some additional CAN-C options perhaps present or not in your car:
Headlamp range ...
Distronic ...
Air suspensions....
besides shared modules acting as ad-hoc translators between networks.
CAN-C Distribution block
Use the distribution block to remove the ESP off of the CAN-C distribution or other module you suspect are busted based on scans.
🤞
Last edited by CaliBenzDriver; 04-17-2023 at 12:27 AM.
Sorry took me a bit to get back to this been busy so what exactly am I to be looking for when I unplug prong 4 ? Am I supposed to be rescanning it for faults ?
Sorry took me a bit to get back to this been busy
so what exactly am I to be looking for when I unplug prong 4 ?
Am I supposed to be rescanning it for faults ?
You'd want to test if ESP is working normally or bugging down your CAN-C.
Right now you're busy. This advanced troubleshooting involves a lot of time you don't have.
It's better to drop off the car at MB specialist. They'll have you back on the road in no time.
Last edited by CaliBenzDriver; 04-21-2023 at 12:06 PM.
You'd want to test if ESP is working normally or bugging down your CAN-C.
Right now you're busy. This advanced troubleshooting involves a lot of time you don't have.
It's better to drop off the car at MB specialist. They'll have you back on the road in no time.
so I messed with it more pulled the #47 fuse and now it's starting every single time ... I've tried it 100 times and fires up every time
04-16-2023, 01:20 PM
... ............ no wonder
