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Pete, Mercedes Mechanic
Category: Mercedes
Satisfied Customers: 28250
Experience:  Over 15 years experience as a Mercedes dealer technician
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2010 Mercedes c300 key opens door, but in ignition key will

Customer Question

2010 Mercedes c300 key opens door, but in ignition key will turn, but nothing turns-on or start
Submitted: 2 years ago.
Category: Mercedes
Expert:  Pete replied 2 years ago.
Hi,my name is ***** ***** I will be happy to try to assist you with this.I may need more information in some cases to help with answering your question.
In some cases this can be due to low voltage from the battery.There may be enough voltage to unlock the vehicle but not enough to allow components to turn on or start the vehicle.The other issue I have seen is the electronic ignition switch itself failing.This can be very common as I have had to replace several before.This is the switch the key inserts into on the dash.
The fault codes will need checked with a scan tool to see what code are set and to see if any codes are set for the ignition switch as this will help diagnose this issue here.
I suspect the switch will need replaced which has to be done by a dealer or authorized Mercedes repair center as it needs set up and programmed once installed.
Have the battery checked first to make sure this isn't the cause here.
Thanks Pete
Customer: replied 2 years ago.
tried to boost also used another battery- no help.
Can I use obii tester to find codes or is this only Mercedes dealer codes only ?
cost to replace eis ?
Expert:  Pete replied 2 years ago.
If the boost and battery did not help this sounds more like the EIS.The codes usually need checked with a scan tool that will communicate with all computers in your vehicle or a dealers SDS machine (which is best to use) as most after market scan tools will not read all computers.
The cost can run around $450 for the switch then around 2.5 hours labor to have it replaced and programmed.
One other issue is the electronic steering lock.Sometimes it fails and will not allow the vehicle to start.You usually hear a buzz at the steering column when its working but if you don't hear the buzz when you first insert the key the lock can be the cause needing replaced.
Thanks Pete
Customer: replied 2 years ago.
I am a aircraft mechanic, can I or Mercedes mechanics install it and program it ? Trying to save money...
Expert:  Pete replied 2 years ago.
The set up needs done usually with a dealers SDS computer plugged into your vehicle so unless you have this machine this usually cannot be done yourself.
Thanks Pete