Please note that prices are from £180 depending on the exact fault we find, price may be more. (You will be informed before hand if you wish to proceed.)
Mercedes EIS / EZS Immobiliser Key Module Problems and Repairs
Symptoms we can diagnose and repair are:
- Unable To Turn The Key
- Unable To Start The Car
- Turn The Key – But Car Won’t Start
- Intermittent Ignition Key Faults
- Vehicle not responding to remote
If the EIS unit becomes faulty, the key will not turn & start the engine, this function will be de-activated and the module will be locked for security purposes. This will stop the engine from starting. It is very unfortunate but also a very common problem as there are many reasons as to why these units fail. Some of the most common reasons are listed below:
- Jump Starting Whilst Key Is Inserted
- Power Surge
- Low Battery Voltage
- Damage to key
- Damage to eis
All of the above can cause memory loss or corruption of the EIS module and it cannot be repaired or re-flashed using the usual Mercedes diagnostic systems. At this point most people will advise you to purchase a new ignition unit which can work out extremely expensive and will need programming and coding before it will work
We also provide a replacement eis unit service, we can send you a reconditioned unit fully programmed to your car ready to install and drive should your original eis be beyond repair.
***Please note all EIS repairs take Between 5 – 7 days***
We have a standard check up fee of £60 +vat if we find nothing wrong with your unit or key after testing



