25 Nov, 12

Mercedes EIS Repair – EZS Immobiliser Key Module – ESL + KEY Repair Service

Mercedes EIS (Electronic Ignition Switch) Modules

Mercedes EIS ProblemsThe Mercedes EIS (Electronic Ignition Switch) system is great in theory, the hardware being the switch is like a small socket in the dash to insert your key into – only, it is not a traditional looking key. It is more like a plastic lego-brick with what looks like an infra-red panel at the face of it which is inserted into the EIS socket on the dash. The key has a sequential code to ensure the vehicle is not stolen.

The vehicle will instantaneously carry out a sequence of test handshakes to ensure the correct key has been inserted. Each time the key is inserted, the EIS system will check the key and then ask the ESL (Electronic Steering Lock) system for verification that it accepts the correct key is being used. The ESL system will then look to see if the Engine ECU (Electronic Control Unit) agrees that this is the authorised key being used. – Then and only then, when all three control units agree it is the correct authorised key being used, will it allow the “Turn & Start” function to be activated.

Which Model Mercedes Has The EIS Module

Mercedes-Benz EIS / EZS Testing + Repairs
The EIS module is factory fitted to almost all models and we’re getting units sent in right across the board from C-Class C220 Mercedes to ML’s and E350 Mercedes. You can expect the EIS module to be supported and installed on the following Chassis list:

W164 / W168 / W169 / W202 / W203 / W204 / W208 / W209 / W210 / W211 / W212 / W215 / W219 / W220 / W221 / W230 / W639

Below we have compiled an extensive list of vehicles which we have already seen fitted with the EIS and have had units in for repairs. Don’t worry if your vehicle is not listed as this is not a complete list.

MakeChassisModelEngineEngine CodeFuelYear (From)
MercedesW168A1601700 CDiOM668DE17ARDiesel1998
MercedesW168A1601700 CDiOM668DE17LARDiesel2001
MercedesW168A1701700 CDiOM668DE17LADiesel1998
MercedesW168A1701700 CDiOM668DE17LADiesel2001
MercedesW169A1501500 16vM266E15Petrol2004
MercedesW169A1601500 16v BlueEfficiencyM266E15Petrol2004
MercedesW169A1602000 CDiOM640DE20LARDiesel2004
MercedesW169A1602000 CDi BlueOM640DE20LARDiesel2009
MercedesW169A1701700 16vM266E17Petrol2004
MercedesW169A1802000 CDiOM640DE20LARDiesel2004
MercedesW169A2002000 16vM266E20Petrol2004
MercedesW169A2002000 16v TurboM266E20ALPetrol2005
MercedesW169A2002000 CDiOM640DE20LADiesel2004
MercedesW202C2002000 16vM111E20Petrol1996
MercedesW202C2002000 16v KompressorM111E20MLPetrol1996
MercedesW202C2002200 CDiOM611DE22LARDiesel1998
MercedesW202C2202200 CDiOM611DE22LADiesel1998
MercedesW202C2302300 16v KompressorM111E23MLPetrol1996
MercedesW202C2402400 V6M112E24Petrol1997
MercedesW202C2802800 V6M112E28Petrol1997
MercedesW202C434300 V8 AMGM113E43Petrol1997
MercedesW202C555500 V8 AMGM113E55Petrol1998
MercedesW203C1801800 16v KompressorM271E20Petrol2002
MercedesW203C1802000 16vM111E20EPetrol2000
MercedesW203C2001800 16v KompressorM271E18MLPetrol2002
MercedesW203C2001800 CGi 16v KompressorM271DE18MLPetrol2003
MercedesW203C2002000 16v KompressorM111E20MLPetrol2000
MercedesW203C2002200 CDiOM611DE22LARDiesel2000
MercedesW203C2002200 CDiOM646DE22LADiesel2003
MercedesW203C2002200 CDiOM646DE22LARDiesel2003
MercedesW203C2202200 CDiOM611DE22LADiesel2000
MercedesW203C2202200 CDiOM646DE22LADiesel2004
MercedesW203C2301800 16v KompressorM271E18MLPetrol2004
MercedesW203C2302500 V6M272E25Petrol2005
MercedesW203C2402600 V6M112E26Petrol2000
MercedesW203C2702700 CDiOM612DE27LADiesel2000
MercedesW203C2803000 V6M272E30Petrol2005
MercedesW203C303000 CDi AMGOM612DE30LADiesel2003
MercedesW203C323200 V6 AMGM112E32MLPetrol2001
MercedesW203C3203000 CDiOM642DE30LADiesel2005
MercedesW203C3203200 V6M112E32Petrol2004
MercedesW203C3503500 V6M272E35Petrol2005
MercedesW203C555500 V8 AMGM113E55Petrol2004
MercedesW203CLK2001800 CGi 16v KompressorM271DE18MLPetrol2003
MercedesW204C1801800 16v KompressorM271KE18MLRPetrol2007
MercedesW204C1802200 CDi BlueOM651DE22LARDiesel2010
MercedesW204C2001800 16v KompressorM271E18MLPetrol2007
MercedesW204C2001800 CDi BlueOM651DE18LADiesel2008
MercedesW204C2002200 CDi BlueOM651DE22LARDiesel2009
MercedesW204C2202200 CDiOM651DE22LADiesel2008
MercedesW204C2202200 CDiOM651DE22LADiesel2011
MercedesW204C2202200 CDiOM651DE22LARDiesel2007
MercedesW204C2202200 CDiOM651DE22LARDiesel2007
MercedesW204C2202200 CDi BlueOM651DE22LADiesel2009
MercedesW204C2302500 V6M272KE25Petrol2007
MercedesW204C2502200 CDi BlueOM651DE22LADiesel2008
MercedesW204C2502200 CDi BlueOM651DE22LADiesel2011
MercedesW204C2803000 V6M272KE30Petrol2007
MercedesW204C3003000 CDi BlueOM642DE30LADiesel2011
MercedesW204C3003000 V6M272KE30Petrol2009
MercedesW204C3203000 CDiOM642DE30LADiesel2007
MercedesW204C3503000 CDiOM642DE30LADiesel2009
MercedesW204C3503000 CDi BlueOM642DE30LADiesel2009
MercedesW204C3503000 CDi BlueOM642LSDE30LADiesel2011
MercedesW204C3503500 V6M272KE35Petrol2007
MercedesW204C3503500 CGi V6 BlueM272DE35Petrol2008
MercedesW219CLS2803000 V6M272E30Petrol2008
MercedesW219CLS3003000 V6M272E30Petrol2009
MercedesW219CLS3203000 CDiOM642DE30LADiesel2004
MercedesW219CLS3503000 CDiOM642DE30LADiesel2008
MercedesW219CLS3503500 V6M272E35Petrol2004
MercedesW219CLS5005000 V8M113E50Petrol2004
MercedesW219CLS5005500 V8M273E55Petrol2006
MercedesW219CLS55 AMG5500 V8 KompressorM113KE55Petrol2004
MercedesW210E2002000 16vM111E20Petrol1995
MercedesW210E2002000 16v KompressorM111E20MLPetrol1997
MercedesW210E2002000 16v Kompressor EVOM111E20EVOPetrol2000
MercedesW210E2002200 CDiOM611DE22LARDiesel1998
MercedesW210E2002200 CDiOM611DE22LARDiesel1999
MercedesW210E2202200 CDiOM611DE22LADiesel1998
MercedesW210E2202200 CDiOM611DE22LADiesel1999
MercedesW210E2402400 V6M112E24Petrol1997
MercedesW210E2402600 V6M112E26Petrol2000
MercedesW210E2702700 CDiOM647DE27LADiesel1999
MercedesW210E2802800 V6M112E28Petrol1997
MercedesW210E3203200 CDiOM613DE32LADiesel1999
MercedesW210E3203200 V6M112E32Petrol1997
MercedesW210E4204200 V8M119E42Petrol1996
MercedesW210E4304300 V8M113E43Petrol1997
MercedesW210E5005000 V8M119E50Petrol1996
MercedesW210E555500 V8 AMGM113E55Petrol1997
MercedesW210E606000 V8 AMGM119E60Petrol1996
MercedesW211E2001800 16v KompressorM271E18MLPetrol2003
MercedesW211E2001800 16v KompressorM271E18MLPetrol2006
MercedesW211E2002200 CDiOM646DE22LARDiesel2003
MercedesW211E2002200 CDiOM646DE22LARDiesel2006
MercedesW211E2202200 CDiOM646DE22LADiesel2002
MercedesW211E2202200 CDiOM646DE22LARDiesel2006
MercedesW211E2202200 CDiOM646DE22LARDiesel2007
MercedesW211E2402600 V6M112E26Petrol2002
MercedesW211E2702700 CDiOM647DE27LADiesel2002
MercedesW211E2803000 CDiOM642DE30LARDiesel2006
MercedesW211E2803000 V6M272E30Petrol2005
MercedesW211E2803200 CDiOM648DE32LARDiesel2005
MercedesW211E3203000 CDiOM642DE30LADiesel2005
MercedesW211E3203200 CDiOM648DE32LADiesel2003
MercedesW211E3203200 V6M112E32Petrol2002
MercedesW211E3503500 V6M272E35Petrol2005
MercedesW211E4204000 CDiOM629DE40LADiesel2006
MercedesW211E5005000 V8M113E50Petrol2002
MercedesW211E5005500 V8M273E55Petrol2006
MercedesW211E55 AMG5500 V8M113E55MLPetrol2003
MercedesW164ML2803000 CDiOM642DE30LARDiesel2005
MercedesW164ML3003000 CDiOM642DE30LARDiesel2009
MercedesW164ML3003000 CDiOM642DE30LARDiesel2010
MercedesW164ML3203000 CDiOM642DE30LADiesel2005
MercedesW164ML3503000 CDiOM642DE30LADiesel2009
MercedesW164ML3503000 CDiOM642DE30LADiesel2010
MercedesW164ML350 BlueTec3000 CDiOM642DE30LADiesel2009
MercedesW164ML3503500 V6M272E35Petrol2005
MercedesW164ML4204000 CDiOM629DE40LADiesel2005
MercedesW164ML5005000 V8M113E50Petrol2005
MercedesW164ML5005500 V8M273KE55Petrol2008
MercedesW164ML63 AMG6200 V8M156E63Petrol2006
MercedesW220S2802800 V6M112E28Petrol1998
MercedesW220S3203200 CDiOM613DE32LADiesel1999
MercedesW220S3203200 CDiOM648DE32LADiesel2002
MercedesW220S3203200 V6M112E32Petrol1998
MercedesW220S3503700 V6M112E37Petrol2002
MercedesW220S4304300 V8M113E43Petrol1998
MercedesW220S4304300 V8M113E43Petrol2003
MercedesW220S5005000 V8M113E50Petrol1998
MercedesW220S5005000 V8M113E50Petrol2003
MercedesW220S55 AMG5500 V8M113E54Petrol1999
MercedesW220S55 AMG5500 V8 KompressorM113E54MLPetrol2002
MercedesW220S600 TwinTurbo5500 V8M275KE55LAPetrol2002
MercedesW220S65 TwinTurbo AMG6000 V12M275KE60LAPetrol2004
MercedesW221S3003000 V6M272E30Petrol2006
MercedesW221S3203000 CDiOM642DE30LADiesel2006
MercedesW221S350 Blue3000 CDiOM642DE30LADiesel2009
MercedesW221S350 BlueTec3000 CDiOM642DE30LADiesel2009
MercedesW221S3503500 V6M272E35Petrol2006
MercedesW221S400 Hybrid3500 V6M272E35Petrol2009
MercedesW221S4204000 CDiOM629DE40LADiesel2006
MercedesW221S4504600 V8M273E46Petrol2006
MercedesW221S500 TwinTurbo Blue4600 V8M278DE46ALPetrol2011
MercedesW221S5005500 V8M273E55Petrol2005
MercedesW221S600 TwinTurbo5500 V12M275KE55LAPetrol2006
MercedesW221S63 TwinTurbo AMG5500 V8M157DE55LAPetrol2010
MercedesW221S65 TwinTurbo AMG6000 V12M275KE60LAPetrol2006
MercedesW639Viano V2002000 16vM111E20Petrol1999
MercedesW639Viano V2002200 CDiOM646DE22LADiesel2003
MercedesW639Viano V2002200 CDiOM646DE22LADiesel2006
MercedesW639Viano V200 Blue2200 CDiOM651DE22LARDiesel2010
MercedesW639Viano V2202200 CDiOM646DE22LADiesel2003
MercedesW639Viano V3003000 CDiOM642DE30LADiesel2006
MercedesW639Viano V3203200 V6M112E32Petrol2003
MercedesW639Viano V3503500 V6M272E35Petrol2007
MercedesW639Viano V3503700 V6M112E37Petrol2004
MercedesW639Vito 1092200 CDiOM646DE22LARDiesel2003
MercedesW639Vito 1092200 CDiOM646DE22LARDiesel2006
MercedesW639Vito 1112200 CDiOM646DE22LADiesel2003
MercedesW639Vito 1112200 CDiOM646DE22LADiesel2006
MercedesW639Vito 111 Blue2200 CDiOM651DE22LARDiesel2010
MercedesW639Vito 1152200 CDiOM646DE22LADiesel2003
MercedesW639Vito 1203000 CDiOM642DE30LADiesel2006
MercedesW639Vito 1223200 V6M112E32Petrol2003
MercedesW639Vito 1233500 V6M272E35Petrol2007
MercedesW639Vito 1233700 V6M112E37Petrol2004

Mercedes EIS / EZS Immobiliser Key Module Problems


  • Unable To Turn The  Key
  • Unable To Start The Car
  • Unable To Unlock Steering Lock
  • Can Turn The Key – But Car Won’t Start
  • Intermittent Ignition Key Faults
  • Won’t Start When Cold


If the EIS unit becomes faulty, the “Turn & Start” function will be de-activated and the module will be locked for security purposes. This will stop the vehicle from starting. It is very unfortunate but also a very common problem as there are many reasons as to why these units are failing – most are due to human error. Some of the most common reasons are listed below:


  • Jump Starting Whilst Key Is Inserted
  • Power Surge
  • Low Battery Voltage


All of the above can cause memory loss to the EIS module and it cannot be repaired or re-flashed using the Mercedes STAR diagnostic system. At this point, you would have been advised to purchase a new unit which can work out extremely expensive when working out the total bill with programming and labour inclusive with VAT.


One of the main problems is the Motorola CPU chip which fails, even the newer batch of EIS modules have the same processor fitted so fitting a new module won’t solve the problem entirely, it’s how you look after the vehicle which plays a big part.

Mercedes-Benz EIS / EZS (Electronic Ignition Switch) Module Repairs

Mercedes EIS Fault - Car Won't Start
We can remanufacture your existing EIS Module unit and save you a lot of money. We thoroughly test & repair all EIS modules to ensure we locate the faults and rectify them completely. When the unit is returned to you, you will not be required to reprogram or re-calibrate the unit – simply plug & play.

After we have repaired your EIS module, you will be able to insert the key, turn the key and start the vehicle with no troubles at all. We do however recommend that you check the battery supply voltage and wiring to the EIS unit prior to installation to ensure there are no faults on the vehicle which could potentially cause failure of the replacement / repaired unit.

All repaired EIS modules are returned with our full Lifetime warranty.

Commonly Asked Questions

  • What if it is my ESL or Key that’s faulty – What should I do?
    We always recommend sending all three parts to us so that we can independently test the units and also test them in circuit alongside each other. We can remanufacture all three parts if required and any repaired units are returned with a Lifetime warranty for complete peace of mind.
  • Will Mercedes EIS programming be required?
    No – we backup all the programming data before remanufacturing the units. Our remanufactured units are returned fully plug & play and will self-calibrate when fitted back to the vehicle.
  • Can you offer a Mercedes EIS replacement?
    Certainly – if your unit is for any reason beyond repair, we can offer a replacement unit and program it on our bench so that no further coding is required when fitting to the vehicle.
  • I’ve been told my model of Mercedes does not have an ESL?
    Not all Models are fitted with an ESL, some models are controlled through the auto gearbox system and in such cases we will only require the EIS and ignition Key.
  • Do you have a Mercedes EIS removal guide?
    No – we do not offer any removal / fitting instructions and always recommend that the removal and fitting is carried out by a competent technician.

Checkout our list of the most common part numbers below. Don’t worry if your part number is not listed, this is not a complete list and there are many more we have seen and successfully repaired. For more information, please call us on 0844 847 9999 or alternatively, send us an email.

Part NumbersPart NumbersPart Numbers
3300.0301210 545 02 08 Q5639 545 01 08
3300.2301210 545 00 084033861060206133
3300.0201215 545 02 08639 545 05 08
3300.22.05211 545 10 088000305550206123
3300.1109215 545 08 082035869051606106
3300.2418209 545 19 086014913971606128

Tags : 2095451908, 2105450008, 2105450208Q5, 2115451008, 2155450208, 2155450808, 3300.0201, 3300.0301, 3300.1109, 3300.22.05, 3300.2301, 6395450108, 6395450508, Mercedes W203 EIS Module Faults - Car Won't Start, Mercedes W203 EIS Module Repairs, Mercedes W208 EIS Module Faults - Car Won't Start, Mercedes W208 EIS Module Repairs, Mercedes W209 EIS Module Faults - Car Won't Start, Mercedes W209 EIS Module Repairs, Mercedes W210 EIS Module Faults - Car Won't Start, Mercedes W210 EIS Module Repairs, Mercedes W211 EIS Module Faults - Car Won't Start, Mercedes W211 EIS Module Repairs, Mercedes W215 EIS Module Faults - Car Won't Start, Mercedes W215 EIS Module Repairs, Mercedes W219 EIS Module Faults - Car Won't Start, Mercedes W219 EIS Module Repairs, Mercedes W220 EIS Module Faults - Car Won't Start, Mercedes W220 EIS Module Repairs, Mercedes W230 EIS Module Faults - Car Won't Start, Mercedes W230 EIS Module Repairs.
549 thoughts on “Mercedes EIS Repair – EZS Immobiliser Key Module – ESL + KEY Repair Service
  • I have a 2008 c300 sedan. The key unlocks/locks the doors, but it will not start the car, and the steering wheel is locked. Was told it was the EIS, the key is worn and I only have one. What can you do to remedy this? Can I get another key when you repair this switch?

    • Hello Bill

      Thank you for your enquiry,

      We have sent you an email with full details and pricing.

      Kind Regards


  • I have a 2005 Mercedes SLK 200. It wont start, all the warning lights come up but on the Ignition phase There is nothing. The electric Fan starts up and goes to maximum which us very Unnerving. I only have the one key.

    • Hello Graham

      Thank you for your enquiry,

      We have sent you an email with full details and pricing.

      Kindest Regards


  • I Have a Mercedes Vito w639. Key won’t turn in ignition. Have recently jumped started couple of times and replaced key fob shell.

    I dont know If ive damaged key Replacing shell or EIS unit through flat battery/ jump start with key in ignition. Also need spare key?

    Thanks in advance

    • Hello Mike

      Thank you for your enquiry,

      We have sent you an email with more details and pricing.

      Kindest Regards


  • i have a mercedes 2006 with steering lock issues.
    Can you call me please on 0***** to discuss

    Many thanks
    Ronald reid

    • Hello Ronald

      Thanks for getting in touch,

      We have sent you an email with full details and pricing.

      Kindest Regards


  • Hi I have a w220 my 2000 and have a problem where I can’t rotate the key once inserted into the EIS unit. I have correct main battery voltage and even changed the battery just in case. the car unlocks with the remote . any idea if this could be repaired ? if so an estimate for repair would be appreciated.

    • Hello Paul

      Thank you for your enquiry,

      We have sent you an email with full details and pricing.

      Kindest Regards


Leave a Reply

Your email address will not be published. Required fields are marked *