kevsmercerdes

I have an '03 SL500 that will start via Keyless Go, but won't allow either of my 2 remote keys to turn in the ignition (EIS). The problem first occured after lowering the top from outside with the remote...no problem there. The next day, I had a smoke outside of the SL with the windows down and radio playing (car shut-off by keyless shifter button...re-pushed the radio's power button to keep it on after shuting down).

Upon finishing the cig I pushed the power button on the radio to shut it off, and inserted the remote key in EIS to raise the windows, but the key would not turn.

Replaced remote batteries, but key wouldn't lock/unlock or work in EIS.

Used the 2nd remote key and lock/unlock works fine. So I figured the first key had gone bad.

Car starts via keyless go, but remote key(s) won't start or turn the EIS.

Starter and consumer battery fully charged. Fuses inspected.

I never, ever usually use the remote key to start the car. Is it possible it's sticky from non-use?

Also, shouldn't the keyless go fail if the EIS is dead?

Thank you for your input.

PS. Anyone know how to access the "user name edit"? I had a typo when registering...

ch33sehead

Did you ever solve this?

kidd415

I have a 2003 sl500 and key didnt turn i put a hair dryer to ignition for ten min and the key turned in the EIS.

ch33sehead

Any idea why that worked?

kidd415

I dnt know why it worked but after reading ppl say it happened on cold days i think EIS gets to cold to work. Car powers key, key just unlock doors, car can start without Battery. Something in EIS dont connect r power on when cold and your EIS is the cars security to whole car. Benz needs to fix they cars.....from shocks to EIS only major problem all benz have in common

jbc247

Just had the same problem and the hair dryer trick worked. Thank yall!

kidd415

IDK why it works.
I think it's a recall issue. I did that 10yrs ago.
Glad it worked out for ya, just not a good look when u have a passenger in car. On cold days just go to car 10mins b4 passenger 😆
Go to MB and ask them why is it, with blow dryer in ur pocket....🤣😂

Bismarck

I am dealing with a simlar problem at the moment with a 2003 R230 - totally random refusal to unlock/lock the car, and/or turn in the lock/and or do anything. According to people in UK who repair the EIS (electronic ignition switch) this can be caused by damp/cold/low voltage from the services battery/water leaks into the footwells and/or the boot/trunk. Because the EIS has links to just about every electronically controlled function in the car the cadence of faults is legion.
Now the lock removal tool has arrived, my EIS is about to the taken out of the car (by me) and sent to a specialist repairer (with both keys) for it to be fixed and reprogrammed.
Wish me luck.

MikeJ65

On the R230, you just need power to the EIS (and a good EIS with matching key) for the key to turn. CAN communication is necessary for the car to start, but not for the key to turn.

Bismarck

It's the 'good EIS' bit that is causing me problems. Anyway I have removed it (easy but fiddly) and it will go to a specialist repairer in Leicester (UK) tomorrow.

jbc247

I assume it means the part is failing. Am I correct with that assumption? Planned to get it replaced to prevent from happening again.

PDOGS SL550

When I insert the Key Fob into the Ignition and the Ignition is in the A position alll the instrument lights come on and the car has full power as if the ignition is in the C position but I can't turn the Key Fob out of the A position and the Starter never turns over. The power only stays on for 30 seconds and a complete shut down of the power happens like I disconnected the battery. The same thing happens when I hit the Push to Start Button on the Gear Shifter as long as I have the Key Fob close to the Grear Shifter making it impossible to use the Scanner tool. Is there a Relay or Module that will cause this to happen any help will be much appreciated

kidd415

To me it seems like a different issue and sounds like part is going out.
best just to get fixed a dealership.

Bismarck

Update on the above - repaired EIS refitted and all functions restored except for remote locking. The mechanicals of the locks all appear to be working as they lock/unlock from inside and lock automatically when at 10 mph+ (or whatever).
I am assuming (dangerous I know!) that because the keys have been reprogrammed to work with the repaired EIS they have to be re-synched to the car so need to find out how that is done - I have heard it said that I should put the key into the EIS and then press a button x 2 within 4 secs - but no advice on which button or whether the key should be turned at all. Anyone know? May have to RTFM but that book is useless...

EDIT:
Tracked the problem down to a faulty services battery. It had spent all its life on a CTEC charger which hid the problem as it just about OK overnight providing there isn't a frost.
New services battery from Mercedes, which is essential, on the shelf at MB Salisbury for £210 all in.