It finally happened. EIS/ESL failure. Thank you Mercedes!
2008 C230 with only 69,000 kilometers on the odometer.
No whirring sound from the ESL when the key is inserted. I tried both of my keys and both have new batteries. The key can turn but nothing happens so maybe not ESL. I have noticed the sound of the little motor in the ESL getting less loud and seems to disengage slower lately for the last couple of months. When I remove my key I can hear a faint ticking noise for about 10 seconds afterward.
Instruments light up and headlights can be turned on. Battery tests at %100 and is new.




Myne actually failed a week after it went for a service(+/- 50 000Km..) under gurantee, and I think it was about the 3rd start after that, had not used the car during the week after service. It worked in my garage, at the bank, park at a shopping centre, get back, fail. 3 weeks+ later itwas fixed after I proved again to them I was the owner, and actually bought it from them.My oldest vehicle had its replaced at over 250 000km, and that was a million more startups, seeing I used it mostly in town short trips.
If I had it correctly, I may be wrong, Mercedes had the manufactured lock outsourced, meaning they dont manufacture it themselves, but I may be wrong, would like to know in any case.
This failure was totally unexpected, and could have had me stranded in a dangerous place, for me it was a shock in reliablity. Every time I drive this car that failure is in the back of my mind. Its going well at the moment, but still.
1st vehicle I owned that left me with this looming feeling.
Last edited by Moto_Guzzi; Nov 9, 2017 at 02:35 PM.
Oddly enough ESL was open so I could turn the steering wheel.
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Myne actually failed a week after it went for a service(+/- 50 000Km..) under gurantee, and I think it was about the 3rd start after that, had not used the car during the week after service. It worked in my garage, at the bank, park at a shopping centre, get back, fail. 3 weeks+ later itwas fixed after I proved again to them I was the owner, and actually bought it from them.My oldest vehicle had its replaced at over 250 000km, and that was a million more startups, seeing I used it mostly in town short trips.
If I had it correctly, I may be wrong, Mercedes had the manufactured lock outsourced, meaning they dont manufacture it themselves, but I may be wrong, would like to know in any case.
This failure was totally unexpected, and could have had me stranded in a dangerous place, for me it was a shock in reliablity. Every time I drive this car that failure is in the back of my mind. Its going well at the moment, but still.
1st vehicle I owned that left me with this looming feeling.
I was just saying to my wife a short while ago that this will eventually happen so I should start putting cash away here and there so it is not such a kick in the *****. I have low kilometers so I figured I was a year or two away from this happening.
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Anyway, you are so lucky that it failed in your garage. There are much worse scenarios
It is a TRP (Theft Relevant Part), so has to be ordered with ID and comes pre-programmed from the key center in the Texas PDC, with a workshop key for programming.
I was just saying to my wife a short while ago that this will eventually happen so I should start putting cash away here and there so it is not such a kick in the *****. I have low kilometers so I figured I was a year or two away from this happening.
This is a DIY, YouTube has instruction how to remove steering column and Esl motor.
Last edited by Demvang; Nov 10, 2017 at 11:52 AM.
Thanks
This is a DIY, YouTube has instruction how to remove steering column and Esl motor.
Amazon also has them for about $19 CAD. Who is to say the replacements are any better than the original?
All China garbage no doubt.
This is my understanding of how the start authorization system operates:
- Key recognized
- Steering Wheel unlocked (assuming it was locked)
- Key rotation allowed
- Instruments receive power (instrument panel lights come on) and signals are generated to check Coolant Temperature Sensor (ECT), Crankshaft position sensor (CKP), and a signal is sent to the starter relay to power up the starter
Again, there are way too many variables for anyone to be able to diagnose this issue without hooking up to STAR and reading fault codes if any, and even then, there are DAS tests that must be run before one can establish which part of this extensive starting system is causing the failure.
All that said, and just like any other diagnostic procedure, and rather than starting out by assuming the worst most expensive possibility, you start out with least expensive and move up the line until you get the issue resolved. In this case, you have got fuses, starter relay/solenoid, CKP, Clutch Switch (if your car is manual otherwise, if it is auto then it could be the transmission lock cable), battery (even though you think its new, you have no idea how much power it is providing or whether something caused a large drain), starter motor... Then jump up to EIS and/or ESL.
For your sake, I hope I am right... But I must warn you that I have been wrong before. Good luck either way...




This is my understanding of how the start authorization system operates:
- Key recognized
- Steering Wheel unlocked (assuming it was locked)
- Key rotation allowed
- Instruments receive power (instrument panel lights come on) and signals are generated to check Coolant Temperature Sensor (ECT), Crankshaft position sensor (CKP), and a signal is sent to the starter relay to power up the starter
Hi there can you elaborate on this what I noticed on myne.
....My instrument lights came on....
....I could lock/unlock the car......
.....Battery was ok at that stage, replaced 4+ years later only.......
1a.....Key inserted, no wring sound, silence, key no turn.
1b.....I assume key may have been recognised(silence), but because the lock/ESL was faulty, it has no movement to actually implement the result of the key being recognised-Keys was not faulty.
Is this good enough to know the lock ESL is fault-? I very strongly doubt the EIS and the ESL can be faulty at the same time.
On examining my bill(gurantee) it seems they 1st replaced the EIS, then at last the lock(3 weeks), then I was told I can get the car with ID proof etc.
The new ESL/lock sounded faster than the old one before it failed, maybe that can be a determining mechanical clue about the ESL/lock itself-?
Last edited by Moto_Guzzi; Nov 11, 2017 at 09:02 AM.
Hi there can you elaborate on this what I noticed on myne.
....My instrument lights came on....
....I could lock/unlock the car......
.....Battery was ok at that stage, replaced 4+ years later only.......
1a.....Key inserted, no wring sound, silence, key no turn.
1b.....I assume key may have been recognised(silence), but because the lock/ESL was faulty, it has no movement to actually implement the result of the key being recognised-Keys was not faulty.
Is this good enough to know the lock ESL is fault-? I very strongly doubt the EIS and the ESL can be faulty at the same time.
On examining my bill(gurantee) it seems they 1st replaced the EIS, then at last the lock(3 weeks), then I was told I can get the car with ID proof etc.
The new ESL/lock sounded faster than the old one before it failed, maybe that can be a determining mechanical clue about the ESL/lock itself-?
The first step to the starting cycle is to authorize/identify the key. If that does not happen, then the key is not going to turn. And you cannot proceed to the next step.
If you cannot proceed to the next step, it could be a slew of problems including a bad key, bad EIS, bad ECU, bad front SAM, bad ESL, dead battery.... amongst other things. So whether you hear a "whirring" sound or not does not always mean it is ESL!
The second step is to unlock ESL. And if ESL is defective/nonresponsive, or if it is any of the several problems that I described ^^above^^ then you cannot proceed to the next step which is to allow the key to turn.
Conversly, there may be times when the key is allowed to turn but this does not necessarily mean that EIS and ESL are working like they should. It could be that EIS was not supposed to allow the key to turn but the mechanism that prevents the key from turning is the defective element.
I don't think anyone can say for certain whether ESL's failure is always mechanical or always electronic... For all we know, it could simply be the connector that communicates with ECU that is faulty, which means it is neither the motor (mechanical) nor the board that controls ESL functionality (electronic). This is especially true on a unit that was replaced rather than had an independent (non-dealer) shop open it up and replace the motor.
Following that same logic, and in answer to your question:
Until the car is in the shop, connected to STAR (or similar device) showing an indication (a fault code) of what the problem is, no one can determine whether it is ESL or EIS that has failed simply based n "whirring" sound or lack thereof, or based on any one symptom on its own.
So was the first repair the correct diagnosis? Or had it been ESL all along? Or was it both had gone bad at the same time? Who knows...
Back to the "whirring sound" and using that as a way to diagnose this problem.... The whole idea of it "often being ESL, and if it is ESL then it is due to the fact that Mercedes Benz outsourced its ESL motors to a cheap Chinese manufacturer, and therefore these motors must be replaced otherwise ESL failure is imminent" was propagated by one independent shop owner who posted here on these forums in hopes of drumming up his "emulator" business. My guess is, all that did was to create a market for many eBay seller who are now competing as to who can sell their cheaply made Chinese motors for less!
Go to eBay and search for "ESL motor" and you'll see what I mean! (Search results)
Heck, they even came up with a tool to help insert that gold colored spiral over the motor shaft...
The question I would have then is if a cheap Chinese made motor was the cause of ESL failure, what is the point of replacing it with yet another cheap Chinese made motor that will presumably fail again sooner than later?




My problem with this Sudden Death situation, is thats it is obviously a design failure of some sort, either design, or manufacture quality.
Measured agains far "inferior" and much lower priced, this is not on for the cost of the owner, even if it fails just short of 200 000Km.
I never encountred a premature failure of this nature on any vehicle I owned, all of them they reached a stage at around 300 000Km something in this regeon is acceptable. Below 100 000km is not acceptable at all.
This is my understanding of how the start authorization system operates:
- Key recognized
- Steering Wheel unlocked (assuming it was locked)
- Key rotation allowed
- Instruments receive power (instrument panel lights come on) and signals are generated to check Coolant Temperature Sensor (ECT), Crankshaft position sensor (CKP), and a signal is sent to the starter relay to power up the starter
Again, there are way too many variables for anyone to be able to diagnose this issue without hooking up to STAR and reading fault codes if any, and even then, there are DAS tests that must be run before one can establish which part of this extensive starting system is causing the failure.
All that said, and just like any other diagnostic procedure, and rather than starting out by assuming the worst most expensive possibility, you start out with least expensive and move up the line until you get the issue resolved. In this case, you have got fuses, starter relay/solenoid, CKP, Clutch Switch (if your car is manual otherwise, if it is auto then it could be the transmission lock cable), battery (even though you think its new, you have no idea how much power it is providing or whether something caused a large drain), starter motor... Then jump up to EIS and/or ESL.
For your sake, I hope I am right... But I must warn you that I have been wrong before. Good luck either way...
Yes, jiggling the steering wheel and banging on the steering column has reportedly worked a few times for a couple of people. For a more direct hit, the steering lock itself is located along the line of the steering column, above the cover that separates the bottom of the dash from the footwell area, and right above the brake pedal. However, 2 things to keep in mind are:
1) Indiscriminately banging on the underside of the dash is likely to cause some sort of damage to the huge collection of electronic components that is built-in to that area, and...
2) This is not, by any means or measure, a permanent fix.
And so in the interest of voiding that sinking feeling again, you'd be well advised to get your car to MB for proper diagnosis and any needed repairs.
Its only done 47,000 kms. I love this car but its utter garbage..no faith in it when its been towed so many times since new. Mercedes should come clean and replace these defective units at no cost.
So be warned that the replacement part as @ 2016 was still crap!
In addition I am about to replace the front shock absorbers and struts for the second time since new. I am a careful driver so its not due to mistreatment.
Oh and my headlight switch is defective and caused battery failure. The lights come on when the car is unattended. Its necessary to leave the switch in the auto position to avoid this.





