austingtir

E550 ignition not unlocking and key not operating central locking anymore.

This is a car I bought as a repair it was on its *** with the airmatic flat. I removed the pump and semi reconditioned it by replacing the piston ring and honing the bore. It appeared to pump the tank up and shut off. I left it to allow the pump to cool down after the rebuild. Opened the door again 15 min later and it pumped for a shorter period of time and the rear started lifting but then the pump shut down as said it only ran for a short period of time.

Thats when the problems with the ignition not working and then after I pulled the key apart and tried cleaning the IR sensor and inside the key body then central locking didnt work either.....

I connected my star diagnostics and I have attached some pics of the results.

Its showing a code 37 in the EIS? And the star diagnostics work I did on the EIS showed me : Output terminal 15c component N73 (EIS [EZS] control unit.

austingtir

So as said I got two issues first is ignition not functioning. second is airmatic pump doesnt want to pump for more than a second now even in star diagnostics and telling it to fill the struts it will just start to pump for a second or less and then its off.

Before the ignition failed I could open the door and the airmatic would try to pump up as per normal and the dash would light up you'd hear the usual electrical clicks behind the dash. Now the dash does light up on Drivers door opening but only a vague electrical noise not the clicks of relays etc as before.

Obviously the ignition is my primary worry atm. I was thinking its the key but now after seeing this scan result its obviously something to do with this output terminal 15c failure. Or have I got that wrong and its a simple key failure? I only have one key.

I have checked fuses but not relays.

Does anyone have the shop manual section that covers this 15c failure and the component n73? And can give me some hints on how to attack this??

Should I stump up and just order a new key from MB or should I investigate the 15c and N73 first?

konigstiger

15c should not be energized with key removed so in effect it seems EIS is not receiving key although expensive I suggest key replacement and if for some reason it is not key you will have second key that may be needed for future diagnostics.

rapidoxidation

Is your battery fully charged?

austingtir

Yes it was dead flat but I charged it over two days with a ctek and it seems ok. Tests ok with my solar battery tester.

I also disconnected it overnight to let the computers reset and reconnected it.

Also tried a known good battery temporarily.

Charged the original e550 battery and put it back in it tests ok.

austingtir

That test in star tell you to install and remove the key multiple times. I believe that photo is the last stage of the test with the key installed in the ignition.

So yeah its likely either the Key or the EIS or both?


So no chance its something like a relay or bad wiring on the car?

austingtir

I just had the key scanned with an autel key scanner system. The infrared worked after a couple tries. The Rf while pushing the buttons didnt seem to but he wasnt sure if was something to do with the autel scanner.

So in theory the key is maybe ok either way when stuck in the ignition it should work so now we are suspecting the EIS ignition box.

I am now going to remove the EIS box as I have spare one and this guy has suggested he can remove the chips and swap them between the two modules and we'll try that before I go about ordering new components which will obviously be way more $$$$