Mercedes EZS EIS Ignition Switch Problems, Causes, and Solutions. Faulty Mercedes Ignition?

Faulty Mercedes Ignition problems/faults

Faulty Mercedes Ignition/steering locks.

Is your Mercedes steering lock stuck? or got a Faulty Mercedes Ignition?

Has your Mercedes key suddenly stopped working?

Read below for Mercedes EZS EIS Ignition Switch Problems, Causes, & Solutions. Faulty Mercedes Ignition Fixes/repairs.

A problem that Mercedes-Benz owners may face is the key no longer turns in the ignition. This issue is often caused either by a defective key, bad module, a failed Electronic Ignition Switch (EIS) also known as the EIS-EZS or a bad steering lock module (ESL). This problem can affect various Mercedes-Benz models including E-Class, S-Class, C-Class, CLK-Class, ML-Class, SL-Class, etc.

Possible symptoms of a failed Mercedes-Benz Steering lock or Ignition switch include:

If you have had the car scanned at a garage for fault codes you may have seen some of the following:

Our technicians will run a diagnostics check to see if the fault is the key, ignition, steering lock, or something else entirely before commencing any work.

Common causes of Faulty Mercedes Ignition switches and Mercedes Steering locks. EIS/ELV

The electronic Mercedes steering lock can be faulty, a common fault on the W204/W207/W212 chassis.
Often the motor burns out and needs replacing.

Mercedes-Benz ignition switch (often referred as immobilizer module) can become faulty and in some cases due to user error. For example, some common reasons why the ignition module failed are:

What To Do ?

During any of the above scenarios, the EIS-EZS may lose its memory. While it can be diagnosed with a Diagnostic Scanner used at dealerships, it can’t be repaired with a scanner. Even Mercedes dealers don’t repairer a bad EIS-EZS modules. They will recommend that the module be replaced. That’s not necessarily the only solution, Call Loxtra Auto locksmiths to find out our next available appointment.

We can address any of these issues at the roadside to get the car working again saving you a tow trip to the dealer, not to mention a big saving in both time and money.



Models affected: Mercedes Sprinter W906 M.Y. 2006-2013.
Common issues: steering column lock faulty or faulty key.
As a key and electronic steering column lock are parts operating on every cycle of ignition, they do wear out en eventually fail.


Modern vehicles are fitted with an electronic steering lock module which is an anti-theft device. It is fitted along the steering column, usually about midway through it. The lock module is controlled by the electronic ignition switch. When the ignition switch module receives the correct identification signal from the key, it sends a signal to the electronic lock to unlock the column. Inside, the lock is engaged and disengaged by a mechanism operated by a tiny electric motor which is part of it. The steering column lock unit is personalised to the vehicle by programming and can only be done once.


At Loxtra Auto Locksmiths & services in Warrington we have mobile units that can travel to you and rectify this fault at your location. This way, we minimise the inconvenience of not having your van on the road, and also, we do not require your Mercedes Sprinter to be recovered, which in some situations it may be very difficult.
Our mobile auto locksmith unit can often replace the faulty electronic steering column lock within the same day as we stock new genuine locking modules or supply you with a new ignition key.

Call us today to check how we can get you back on the road if your Mercedes Sprinter has a faulty ESL or a faulty key.
Always have a spare key for your Mercedes it will be very useful when required and will save you time and money in the long run.

How to fix Mercedes Ignition Switch Problems

Step 1
These symptoms can very well be caused by a defective key. If you have a spare key try to see if you are experiencing the same symptoms with the other key. If the other key works, keep using it for a couple of weeks to verify that the issue is really the key and not the EIS.
Step 2
Try scanning your Mercedes-Benz for fault codes. Ideally using a Mercedes Star Diagnostic Scanner. This scanner should still retrieve fault codes when the ignition is off. If you don’t have this scanner or know of a shop that does, a possible alternative would be to use iCarsoft MB II scanner. The only issue here is that if you can’t turn on the ignition, you can’t power on the OBD2 port and the iCarsoft MB II scanner. If the ignition turns on intermittently, consider yourself lucky and scan for codes. Hopefully, there are fault codes that will point you to the problem.
Step 3
Diagnosing Mercedes ignition problems isn’t a simple DIY job. You may consider taking your car to the dealer or an independent shop and have them troubleshoot the problem. If they come to the conclusion that the Ignition Switch (EIS-EZS) is the culprit you will be told that the switch will need to be replaced. This is an expensive repair that can cost several hundred pounds. You have a few options here. Have the dealer install a new ignition switch, and they will program it to match the VIN of your Mercedes-Benz. Many owners go the route of installing ignition switch, ECU, shifter module and other parts from a donor vehicle. You can’t replace the ignition switch only with one from a used Mercedes-Benz. Several parts need to swapped because the stored VIN needs to be the same in all of them.

Third Option for your Faulty Mercedes EIS/ELV

There is also a third option, and it may be the cheapest way to fix Mercedes ignition switch module. We at Loxtra auto locksmiths can repair Mercedes-Benz ignition modules. You can even remove the ignition module from your Mercedes-Benz and ship it us to test and repair the EIS-EZS. Once the module is repaired it is returned to you. Besides the fact that this is a lot cheaper than installing a new ignition module, it also doesn’t require any programming or coding. The VIN stored in the Ignition Module (EIS-EZS) matches that of the car; it’s your old module after all. Just install it and you are ready to go. Or if you don’t want to remove it yourself and send it to us, Give us a call to book an appointment for us to come to you and repair in onsite.
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