Benz-O-Rama

Gents,

Recently, my 2004 E500 has started to exhibit intermittent and sporadic keyless-go starting. The doors will always lock or unlock using this feature but the button on the shifter will sometimes start the car perfectly on the first try, sometimes not at all. And sometimes, I have to push the button 3, 4, 5, 6 times and it'll start. Tried replacing the battery, but no joy. And since the doors always operate as expected, I knew a bad battery was a long shot.

I searched but couldn't find anything useful. I did see something about a bad tail light switch causing keyless-go not to work, which is very strange in it's own right.

Anyway, any ideas?

amdeutsch

Its an alternate action switch that is located in the gearshift handle. Someone posted pics of it on here. Maybe there is an issue with some light corrosion on the contacts and/or the pins the switch plugs into.

Benz-O-Rama

I'll try to dig that picture up, thanks. Sounds like a new shifter knob might be in order. I'm sure that'll be cheap.

Barry45RPM

What does the DIC say during the Keyless Go start sequence failure? "Key Not Recognized" or nothing?

On my '04 I had intermittant failure of the start sequence... sometimes it would quick cranking in mid crank. Turned out it was a bad "Stop Switch". I believe that is the brake light switch actuated by stepping on the brake. Remember that the brake pedal must be stepped on to start. A bad switch can prohibit a start.

Try pressing down harder during a non start as a way of possibly checking for this switch not working properly. It was an easy diagnosis for the techs on my car & the part was in stock.

Benz-O-Rama

Barry,

The MFD says nothing at all. No error messages during start failure. I haven't had it stop in mid crank either. It's almost as if the button the gear shift knob isn't being pressed hard enough. I'll try stomping the brake pedal and see what happens.

MB211

Try removing the shift knob, cleaning contacts and installing a little bit of dielectric (butched that spelling) grease.

Most likely the button is not sending a good signal.....Better (cheaper) to try cleaning before replacing.

MB211

If the stop lamp switch was the fault, the car would still turn on to position #1 and #2, just to start.

Benz-O-Rama

Will do.

This is good info. It's definitely not making it to position 1. More likely its the connection or the shifter itself. I'll monkey around with it this weekend.

Thanks!

malahhaor

I have 2 keys, one works perfectly fine, and the other one only opens doors/trunk, if i try to start the car, tells me key not recognized no matter how many times i push it... go figure, the key must be bad.

Benz-O-Rama

Update:

Problem is definitely in the button/shifter. When it's in the "I don't want to work" mode, and I wiggle the button back and forth while applying pressure, it's starts right up. Same goes when I shut it off. So, either bad shifter/button or, as someone mentioned, bad contacts. I'll pull it apart and take a looksie and see what's what.

Thanks, gents.

DrDrilZ

for some reason mine will sometimes not work when the key is next to my cell phone in my pocket.

Benz-O-Rama

Yep, that's normal RF interference.

Scambo

I have the same issue now with my 2004 E500. Sometimes, the shifter button will work, and sometimes it wont. I move the shifter around, into park, reverse, drive, etc and then back to park to try again, and sometimes it works. Totally kills the cool factor when you have keyless go and you have to get out your keys to start the car!!! Was there ever a final resolution Benzo??

peterpst

I have the same issue. E 270 CDI Estate 2004.
Will only start after jiggling the gear shift left/right while pressing the key.

MB Dealer advice: put in a complete new gear stick knob - parts € 200 plus workshop fees - without a guarantee that this really solves the issue. They refuse to replace the switch only and will not check it either.

The cap on top of the switch can be removed with your fingernails or a credit card or two small screwdrivers - it is a small plastic part - just pull it up gently.
The switch in the gear shift knob can be extracted by pulling it out carefully with a small set of pliers - it is connected in the gear shift axis with two straight golden pins - releases easily. But the switch itself is fine.

Solved today.
The problem was not key related and solved by applying some contact spray on the golden pins of the switch. Re-inserted the switch carefully and put the plastic cap back on. If you know what to do, the entire procedure can be completed in 3 minutes.

Diesel Benz

If this is intermittent, it could be difficult to diagnose but wouldn't the gear lever position switch be the most likely issue? Or even the brake light switch. Testing with the key at the ignition switch could help, if the car starts from the ignition slot but not from the KG button, then the KG switch could be faulty, otherwise unlikely?

Benz-O-Rama

Great information! Thanks!

My key works in the ignition 100% of the time. But now, the keyless go button fails 100% of the time. I'll try the above suggestion.

However, I have another issue. I can no longer unlock either driver side doors, by pulling the handles. Nor, can I lock the car by depressing either lock button on either door on the driver side. The doors on the passenger side and truck lock and unlock as they should.

My wife has been driving this car recently so I haven't had a chance to rip it apart. But, we just got her a new truck this weekend, so she's tossed the keys for the E back to me. I can try to start working on this again, now.

Dema

Bad key should be retrained. Check manual. As I remember you just need to insert it in ignition hole...

Dema

Somebody pointed that failure of keyless go can be issued by car battery. If voltage drops certain level, keyless circuits get cut off. The rest seems working fine, so you may need just check voltage of car battery

zonnies619

i had a similar problem with my 2006 w211 e55 and it turned out to be a bad brake sensor located somewhere by the brake pedal. i received a warning indicator saying something like "service dealer" and my keyless go would only work at random times.

Diesel Benz

This could be the case above too, the brake pedal sensors needs to work with KG if the car is started from the KG button while this is not needed when the engine is started with the key at the ignition slot (as long as the gear selector switch works and detects neutral or parking position).

The door handle issue is very common on W211 models and should not be related to starting issues.

malahhaor

the problem i have is with the driver side door, and once the weather warmed up everything is fine. in the winter when it's cold or fall when it's raining it stops working till weather dries up. And the handle been replaced and still the same thing.

Yuriy Savitskiy

Were you able to figure that issue out? My ‘09 E350 is doing the same thing with driver side door handles and I also have to be in a certain area close to the car for the keyless entry to work with the buttons on the remote. It drives me insane because I think there may be multiple issues going on since the previous owner completely neglected it.

cetialpha5

Did you change the batteries in the remote? When the door handles don't work but the others do, the door handle probably went bad and you need a new door handle. Usually either the lock or unlock function will go first. There's just a thin rubber membrane over the switch and water eventually gets in and corrodes the switch so they go bad. Could also be a problem with the receiver if a few of the handles are out at the same time, but if it's just one handle, it's probably just the door handle.