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I was driving my 2011 c300 4matic on the interstate earlier today when I lost acceleration. I turned the car off afterwards & tried to start it but it was like the engine wouldn’t turn over. A few hours later neither of my two keys would start the car or even get the lights on the dash to light up. There’s no clicking when the key is put into the ignition I just get a message that says “remove key from ignition.” I’ve replaced the battery & I feel like it may be an EIS as far as the car not starting but I don’t believe that would’ve made the car lose throttlw while driving. Can anybody please give me some type of insight?
I was driving my 2011 c300 4matic on the interstate earlier today when I lost acceleration. I turned the car off afterwards & tried to start it but it was like the engine wouldn’t turn over. A few hours later neither of my two keys would start the car or even get the lights on the dash to light up. There’s no clicking when the key is put into the ignition I just get a message that says “remove key from ignition.” I’ve replaced the battery & I feel like it may be an EIS as far as the car not starting but I don’t believe that would’ve made the car lose throttlw while driving. Can anybody please give me some type of insight?
Do you have s scanner (not an inexpensive code reader)? The first place to start would be to scan for trouble codes that could point to the failure.
1-No unlock sound + the Remove Key message points to an ESL failure. But that doesn’t usually lead to loss of power while driving.
2-A rather remote possibility that could cause all the symptoms would be a fuse in the prefuse block blowing and cutting power to the front SAM. But those fuses are large and won’t blow without a catastrophic short in the electrical system.
That’s why s scanner with a dedicated Mercedes scanner is the place to begin.
the battery is 12+ volts for the terminals & the key can turn when I put it in the ignition, just nothing happens when I turn it
In the absence of further diagnostic codes the no crank, no ignition lights and remove key message points to a failed electronic steering lock. Can you still turn the steering wheel? If so disconnect the battery and remove the ESL. You do not want the ESL to lock at this point as it makes removal a difficult task. I recommend you replace the ESL with an emulator for even though failure is likely not connected with the engine cutting out, it is the probable root cause of why you cannot start the car.
With key in the ignition you can turn it to on. But nothing happens.
With the key in and turned to on can you turn the steering wheel? Can you shift the shifter into neutral? if you can turn the steering wheel the ESL seems to be functioning at least.
Theres no mention of hooking up an OBD scanner to check for faults codes. Thats the first thing I would do.
Theres no mention of hooking up an OBD scanner to check for faults codes. Thats the first thing I would do.
That’s the first thing I recommend in post 2 of this thread. But it seems like it’s falling on deaf ears. I make a suggestion and it’s ignored, I kinda just drop out and read the results. These aren’t my kids.
That’s the first thing I recommend in post 2 of this thread. But it seems like it’s falling on deaf ears. I make a suggestion and it’s ignored, I kinda just drop out and read the results. These aren’t my kids.
I don’t have a OBD Scanner at the moment & over the weekend I wasn’t able to get the car towed to a mechanic. It has since been towed to a mechanic & he should be hooking it up to the scanner Friday. I do appreciate all the insight that has been given so far & will keep this thread updated as I learn more.
& Yes the steering wheel moved but I wasn’t able to shift gears until I popped the cover off of the gearshift to get into neutral to get the car towed.
I don’t have a OBD Scanner at the moment & over the weekend I wasn’t able to get the car towed to a mechanic. It has since been towed to a mechanic & he should be hooking it up to the scanner Friday. I do appreciate all the insight that has been given so far & will keep this thread updated as I learn more.
& Yes the steering wheel moved but I wasn’t able to shift gears until I popped the cover off of the gearshift to get into neutral to get the car towed.
I went back and reread my reply. That was pretty rude of me and not helpful at all. My apologies. Looks like I can’t go back and delete it.
I recommend to everyone they get a Mercedes specific obd scanner. I have saved alot of money using mine to diagnose problems with the car. Can get a Launch scanner for $100.
I went back and reread my reply. That was pretty rude of me and not helpful at all. My apologies. Looks like I can’t go back and delete it.
Sir. It's all good in my opinion. We all have busy lives and often only a few minutes to contribute. You've helped a lot of folks and anyone who has read past posts knows this. High 5.
That’s the first thing I recommend in post 2 of this thread. But it seems like it’s falling on deaf ears. I make a suggestion and it’s ignored, I kinda just drop out and read the results. These aren’t my kids.
Originally Posted by Odd Piggy
I went back and reread my reply. That was pretty rude of me and not helpful at all. My apologies. Looks like I can’t go back and delete it.
Forum member Odd Piggy, don't be too hard on yourself, your contributions over the years are appreciated by many. Including me, you also helped answer some of my questions too over the years so thank you for that.
Last edited by W205C43PFL; May 3, 2026 at 04:43 PM.
So I don’t have a code reader still but I did get the car taken to a mechanic & was told I have some misfired cylinder codes showing up. He didn’t do anything to the car sadly so I had it towed back home. Once the car was at my house I had try to test the ignition system & the battery was now dead (Mind you I had just put this new battery in the car the same day after the problems started to arise). So we take the battery out & charge it for a day. We put the battery back in the car, the EIS system unlocked thankfully & the car started but it was a very rough start that followed with a rough idle. When I revved the engine it would smooth out a little but the go right back to the rough idle. A few days later & it would seem like the battery would constantly die & the car wouldn’t even attempt to crank now. I feel like my alternator might be the problem since the battery can’t keep a charge cause last time I check it, it showed 8V while the car was off.
The alternator voltage regulator diodes could be bad. The alternator could still charge, but drain the battery when the engine is turned off. Check at the battery for high discharge current with the engine off. Anything more than 100 milliamps is either the alternator or a high parasitic drain from some other failing component.
Last edited by Odd Piggy; Yesterday at 12:31 AM.
Reason: (sp)
Use a mulitmeter and check battery voltage at the battery posts when the engine is running, should be 13.5v or higher. If it's not then the alternator isn't working.
if you dont already have one get an obd scan tool like the Launch creader. $100 on AliiExpress. It should tell you if there's a fault with the alternator or charging system. And help figure out the rough idle.
Shame the mechanic did not provide you with the fault codes or else we would have something to go off of.
Ever since I replaced my battery a month or two ago I left a battery monitor connected to battery. With the monitor I can see the alternator seems to be functioning fine and the battery holds its charge when parked.
What I see is with the engine running at idle voltage shows around 13.5v. When im driving around the voltage likes to hover around 14v. So im thinking you should see similar results using a multimeter testing the battery voltage in the driveway.
On the graph below the voltage dips is when im stopped at stop light, taking off the voltage goes up then settles back down to 14v as im driving.
I’ll probably order a obd reader at the end of this week so once that comes in then I’ll be able to post whatever codes do appear & try to get a more concrete idea of what the issue may be. & then I’ll be putting the battery back in some time this week cause I took it out yesterday to charge again & then ince it’s put back in, I will test the battery while the car is started.
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