ss3964spd

Symptoms, so far, are these:
No warnings at all on MFD.
Smart key locks/unlocks doors as normal.
Insert key into ignition, everything normal.
Key to Run position, all normal.
Key to Start and release (as normal), starter motor does not run (engine simply does not crank - at all).
Key back to Start and release - nothing.
Turn Key to Off, then back to on and to Start, Engine cranks and starts as normal.

It does not seem to do this when the engine is cold. The only times it has done this is when the engine is warm, but not necessarily at operating temp. And, to make it more fun, it does not do it all the time.

Ideas?

Thanks, Dan

Diesel Benz

Wouldn't the engine crank even if the crankshaft position sensor fails, would just not start? Or would the ECU not start the starter motor if it sees a malfunction (open/closed circuit for CPS)? I'm just wondering because I believe CPS typically behaves first when the engine is warm.

TheRealG

maybe you need a new ignition switch?
G.

ss3964spd

I don't know if the engine would crank with a failed CPS or not DB, but I do think if the ECU prevented the engine from cranking due to a failed CPS, then it would also throw an error on the MFD.

Dan

Diesel Benz

I thought it would not be EIS because it clearly identifies and authorises the key, it would not turn otherwise.

Diesel Benz

I'm not sure about this at all, if you see the list of MFD messages from the user manual, would there be one that would fit to CPS malfunction? Perhaps something like "visit workshop" but if the car does not start, does that message add a lot of value. I'm sure there is no "CPS failure" message specifically.

ss3964spd

Inclined to agree DB. If the ECU knew of a fault I'm sure it would throw something like the catch all "Visit Workshop" message.

Of course, if the engine will not actually start then the "Visit Workshop" message is rather ironic, isn't it?

Funny guys, those Germans.

konigstiger

The engine will start with a faulty sensor and yes, you would see the all-encompassing “Check Engine Light” together with a fault code being stored in the ECU. Have them check the ECU software and update if need be.

Diesel Benz

Of course if the starter motor solenoid was faulty, or the solenoid drive for some reason missing, the engine would not start cranking and I doubt it would through any cluster malfunctions. But for a 2005 car this cannot happen unless it is a flooded car that has not been used for quite some time.

ss3964spd

There is no CEL, there are no MFD messages, there are no sounds being emitted from the starter. There is simply - nothing. Turn the key to start, simply not a peep from the starter.

Dan

konigstiger

Yes, I understood that I was just answering your previous question about a failed sensor keeping the engine from starting and if this would generate a warning message.

“Basically” three factors involved:
(1) Key(s) – Same intermittent recognition problem with both keys
(2) EIS – Intermittent recognition problem
(3) ECU – Check for any stored fault codes, and upgrade software as a starting point

ss3964spd

Ah, gotcha now Konigstiger, think I was having a geezer moment.

I have not yet tried the 2nd key to see if the symptoms remain the same. One thought I did have is that I doubt that the battery in the master key has ever been changed, but I don't know enough about the system to say if the battery even plays a role in key recognition, or if the battery is only used for general remote functions. It's a "2025" battery, yes?

Thanks for everyone's input.

Dan

MB211

Battery plays no role in starting...in fact you can start the car with the battery section pulled out of the key.

Just because the EIS authorizes steering lock to release, does not necc mean it is auth the car to crank. You can check for codes, typically on an EIS malf there will be codes stored for CAN com faults. Also, as previously stated, you could have a key problem.

Diesel Benz

Can you clarify this, in my opinion there is only one sequence of key authorisation, if the key is authorised, the key is allowed to turn in the ignition switch and there is no second key authorisation to allow the car to start.

I guess you mean there may be other reasons why the car does not turn the starter motor on? This I would agree, but which one could be the one for this case?

Always a good idea to try a second key in any case. And you are quite right that the key battery is not needed to make the car start.

ss3964spd

Thanks again for your collective input.

At this point I am just going to have to wait and see. Unless there are codes stored the symptom is not consistent enough to pin it down. In fact, it hasn't done it since Monday evening. I'll update this thread once I have more information.

Thanks,

Dan

Busta Riles

Did you ever get this issue resolved?

FWIW, i was having the same problem for about 6 months in my E55. My Tech decided to switch the relay with another one in the car that does something completely different.

I can't remember which one he switched it with, but he said, this one doesn't need to do the same things that one does, so if it works this way, everything will be fine.

I haven't had the problem since.

beafer

Been having this problem since i took my car in for them to replace a glow plug. Wondering if its just me or intermitten issue with key.

irondad

I'm having the exact same problem as OP and was wondering if anyone else has had the same problem and what the solution was.

Tony46727

+1 having this exact same issue. It started out happening occasionally. Recently, it happens almost every time I start the car. I've noticed that when I insert the key, the wheel moves into place and nothing else. Then when I turn it to position I, nothing happens initially. After several seconds, the MFD comes on as well as the odo. When I turn to position II, again, nothing happens for several seconds, then the selected gear and mode of the transmission comes on on either side of the odo, and the dash lights come on. I can then turn the key to start and it fires right up. It's like there's something holding up the sequence at each detent, and as long as I wait for the process to catch up, everything is fine.

Rene Yau F

I know is an old thread but did anyone found a solution? I've been having the same issue.

elc32955

Hi folks,

Been a while since I posted, but I have the same problem - except mine is an intermittent "crank no start" issue. Fault has been more or less traced to the ECU via scanning. What is happening with me is that when the problem occurs I'm seeing the SRS warning message and the car will always crank, but no start happens. I've been pursuing several forums and I've learned that apparently on this fault that; 1) Other CDI and gas owners have experienced the exact same thing. 2) The fault itself returns when the car is scanned as a ECU module fault, I don't have the exact error code in hand right now. 3) The fault, when it occurs does not allow the ground to get to the fuel pump from what other owners have stated - hence the no-start condition. 4) There is a E320 CDI owner that made an EBAY video that shows a contingency way to start the car when the failure happens by jumpering one of the wires coming off the under-hood electrical center to a ground while cranking (Brown & Yellow, switched SAM ground). I'm guessing it completes the circuit to the fuel pump & allow start & run. Once the car is started, the car will continue to run until shut off, you can pull the jumper after the start & run cycle - car keeps running from what the OP states. After that, it's a crapshoot on re-starting unless you again re-jumper. Google "E320 CDI no start" and the video should come up.

Worse for me is that I have a 05 E320. Apparently the older 211 series of these modules is now supply-exhausted OEM from Mercedes, and in order to get a replacement for the car a newer revision ECU is now called out. The problem is that between 2005 and 2006 the EGR valves were changed, and the newer series ECU will NOT communicate with the older 05 EGR. So.... not only do I have to change out the ECU, if I use a new unit from Mercedes I apparently also have to change the EGR valve assembly as well. Mine is still fine, it was programmed off when the GDE tune was installed years back. Probably a plug-n-play module rebuilder with a warranty is my best option - using the exact same ECU model number, they just close over the configuration and the S.C.U. information.

As many owners have experienced either the exact same or slightly different version of this problem, this leads me to suspect there may be an inherent time bomb in these W211 ECU's. Exactly what triggers it (miles, years, heat and/or high humidity, etc...) remains a mystery, as does the exact part(s) that fail out to cause the condition. More then one owner has alleged Mercedes had QA problems in regards to the wave soldering on the ECU circuit boards. If this is true, maybe we're just looking at a loose wire or a corrupted trace on the board that over time and with normal stressors of running, heat, vibration, etc.... has just given up the ghost. If there is a commonality on the exact fix required for the ECU to become "whole" again, I'd sure like to find it - not only for myself but for other owners as well. If it's just a matter of refreshing a solder joint or trace, I've got a Weller temp-controlled fine soldering iron and a good viewer. I know that there are successful ECU rebuilders out there that make a living off these, so a fix has to be possible. The conundrum is finding out what that exact fix is and whether it can be field-applied. I have much better things to do with my money then to shell it out to a Mercedes dealer for overpriced hardware & services. Or, to an indy for that matter.

So... does anyone have institutional knowledge that can be shared/applied to my problem? Speak ye loudly, oh purveyors of information!! Short of breaking the ECU open myself (which I have not done yet) for an eyeball & ohmmeter inspection, I'm hoping another owner has the solution/fix and we just don't know about it yet.

Thanks
Eric