E55 just died on highway and now wont start!!?
Thread Starter
MBWorld Fanatic!
Joined: Jul 2005
Posts: 3,174
Likes: 19
From: London, UK
No longer stock '06 E55, A3 3.2 Quattro, GLE 400d, R107 280SL, Golf Polo
E55 just died on highway and now wont start!!?
Car died while doing steady 75mph … no limp
mode - car was super smooth before that and running great. Just seemed to lose power to the ECU or other electronics - but battery is 100% - voltage was 14v with car running.
Car cranks very well but shows zero intent to start. Threw numerous codes - but they all cleared. Try crank again and nothing. Then it wont crank at all and cannot get car out of park. Then when trying to crank get message to put car in P or N. Autel then cannot find ECM - on/off and then it can find ECM. Then cycle ignition and it cranks again but still no start.
Spare key same problem. Using ignition or start button same issue.
AI says its a failing ECM or crank pos sensor failure. Battery brand new.
Anyone else have this issue or any ideas?
mode - car was super smooth before that and running great. Just seemed to lose power to the ECU or other electronics - but battery is 100% - voltage was 14v with car running.
Car cranks very well but shows zero intent to start. Threw numerous codes - but they all cleared. Try crank again and nothing. Then it wont crank at all and cannot get car out of park. Then when trying to crank get message to put car in P or N. Autel then cannot find ECM - on/off and then it can find ECM. Then cycle ignition and it cranks again but still no start.
Spare key same problem. Using ignition or start button same issue.
AI says its a failing ECM or crank pos sensor failure. Battery brand new.
Anyone else have this issue or any ideas?
Last edited by stevebez; Feb 27, 2026 at 05:21 PM.
MBWorld Fanatic!
Joined: Jan 2014
Posts: 3,966
Likes: 1,315
From: Republic of Texas
'99 and '05 E55 AMG
Possible CPS but not my first guess.
Engine dying while driving points to fuel pump or electrical system failure. Check for fuel rail pressure when key is turned on. If no or little pressure, check fuel pump relay and harness to fuel pumps.
Issue with gear selector points to shifter module or brake switch.
Could be failed module killing the CANBus. Engine and shifter failure point to CAN-C bus which carries critical info for drive train. Check voltages on Lo and Hi lines and check for short to chassis.
I have some posts on CANBus diagnostics that may assist.
Let us know.
Engine dying while driving points to fuel pump or electrical system failure. Check for fuel rail pressure when key is turned on. If no or little pressure, check fuel pump relay and harness to fuel pumps.
Issue with gear selector points to shifter module or brake switch.
Could be failed module killing the CANBus. Engine and shifter failure point to CAN-C bus which carries critical info for drive train. Check voltages on Lo and Hi lines and check for short to chassis.
I have some posts on CANBus diagnostics that may assist.
Let us know.
Thread Starter
MBWorld Fanatic!
Joined: Jul 2005
Posts: 3,174
Likes: 19
From: London, UK
No longer stock '06 E55, A3 3.2 Quattro, GLE 400d, R107 280SL, Golf Polo
Thanks that very helpful -
Any locations / places to probe for the high low canbus signal.
Will check fuel pump pressure first - weird it would just suddenly die …
Any locations / places to probe for the high low canbus signal.
Will check fuel pump pressure first - weird it would just suddenly die …
Out Of Control!!
Joined: Apr 2019
Posts: 11,927
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
fuel's No1
Car died while doing steady 75mph … no limp
mode - car was super smooth before that and running great. Just seemed to lose power to the ECU or other electronics - but battery is 100% - voltage was 14v with car running.
Car cranks very well but shows zero intent to start. Threw numerous codes - but they all cleared. Try crank again and nothing. Then it wont crank at all and cannot get car out of park. Then when trying to crank get message to put car in P or N. Autel then cannot find ECM - on/off and then it can find ECM. Then cycle ignition and it cranks again but still no start.
Spare key same problem. Using ignition or start button same issue.
AI says its a failing ECM or crank pos sensor failure. Battery brand new.
Anyone else have this issue or any ideas?
mode - car was super smooth before that and running great. Just seemed to lose power to the ECU or other electronics - but battery is 100% - voltage was 14v with car running.
Car cranks very well but shows zero intent to start. Threw numerous codes - but they all cleared. Try crank again and nothing. Then it wont crank at all and cannot get car out of park. Then when trying to crank get message to put car in P or N. Autel then cannot find ECM - on/off and then it can find ECM. Then cycle ignition and it cranks again but still no start.
Spare key same problem. Using ignition or start button same issue.
AI says its a failing ECM or crank pos sensor failure. Battery brand new.
Anyone else have this issue or any ideas?
Go inspect physically :
connections + voltage.
Last edited by CaliBenzDriver; Feb 27, 2026 at 08:01 PM.
MBWorld Fanatic!
Joined: Jan 2014
Posts: 3,966
Likes: 1,315
From: Republic of Texas
'99 and '05 E55 AMG
See attached. The CAN-C junction block is on driver's side under the door sill. Remove plate to gain access to the "tunnel". CAN-C wires are green and green/white. CAN-B wires are Brown and Brown/Red.
You can "read" the voltages on the CAN-C bus using a breakout box connected to the OBD2 port under the dash. Easier that way to attach a multi-meter or CANBus Analyzer.
Last edited by bbirdwell; Feb 27, 2026 at 07:58 PM.
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MBWorld Fanatic!
Joined: Jan 2014
Posts: 3,966
Likes: 1,315
From: Republic of Texas
'99 and '05 E55 AMG
A few links to give you an idea...
https://mbworld.org/forums/e-class-w...is-repair.html
https://mbworld.org/forums/e-class-w...ml#post8958920
https://mbworld.org/forums/w211-amg/...-no-start.html
Pull a search on Amazon for "OBD2 breakout box". Much easier than trying to probe connector blocks.
https://mbworld.org/forums/e-class-w...is-repair.html
https://mbworld.org/forums/e-class-w...ml#post8958920
https://mbworld.org/forums/w211-amg/...-no-start.html
Pull a search on Amazon for "OBD2 breakout box". Much easier than trying to probe connector blocks.
Last edited by bbirdwell; Feb 27, 2026 at 07:56 PM.
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Joined: Feb 2012
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From: Phoenix
222 S-65
OP it died, then cranked; no start. Now no crank no start. Time to plug into Xentry and see what it thinks of itself. Get ahold of Peter... AKA BenzNinja. Buy the equipment and membership. He knows his stuff. Then you own Xentry.
I enjoy being able to give the car a Quick Test any time something happens. Real Mercedes tools. Real information. Real coding. Peter is a wealth of information.
I enjoy being able to give the car a Quick Test any time something happens. Real Mercedes tools. Real information. Real coding. Peter is a wealth of information.
Thread Starter
MBWorld Fanatic!
Joined: Jul 2005
Posts: 3,174
Likes: 19
From: London, UK
No longer stock '06 E55, A3 3.2 Quattro, GLE 400d, R107 280SL, Golf Polo
Coil pack fuse (58) 15amp is blown - tracing the cause of that now.
Thanks for help so far guys. I did wash the engine bay and maybe water got into coils increasing load etc
… but still weird this happens after car been running 30 mins.
Full tank of gas!
Thanks for help so far guys. I did wash the engine bay and maybe water got into coils increasing load etc
… but still weird this happens after car been running 30 mins.Full tank of gas!
Thread Starter
MBWorld Fanatic!
Joined: Jul 2005
Posts: 3,174
Likes: 19
From: London, UK
No longer stock '06 E55, A3 3.2 Quattro, GLE 400d, R107 280SL, Golf Polo
Water in/around coil packs created short and blew fuse…. Car dried out more now, replaced fuse ran it at idle for over ah hour to heat soak it and dry it more and check if it came back. Took for drive and all is good again.
Geezuz one 15A fuse cost me 250£ towing …. Anyhow replacing some of the coil pack clips that have lost their clips…
Thanks for help!
Geezuz one 15A fuse cost me 250£ towing …. Anyhow replacing some of the coil pack clips that have lost their clips…
Thanks for help!
