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

Sinspeed EIS Repair Services

Welcome to Sinspeed’s Mercedes-Benz EIS Repair Service. We specialise in repairing and replacing faulty EIS units for Mercedes-Benz vehicles. Our team of experienced technicians have years of experience in diagnosing and repairing EIS units, and we use only the latest diagnostic equipment and software to ensure that your EIS unit is repaired to the highest standard. Furthermore, we extend our service to the testing and repair of the Mercedes-Benz ESL (Electronic Steering Lock) and Key too!

What Is An EIS & How Does It Work?

The Electronic Ignition Switch (EIS) is a vital component in the Mercedes-Benz vehicle’s security system. It is responsible for controlling the vehicle’s immobiliser, which prevents the engine from starting without the correct key. The EIS is also responsible for controlling other security features such as the central locking system and the alarm.

The EIS works by communicating with the key through a transponder chip. When the key is inserted into the ignition, the EIS sends a signal to the key, which responds with a unique code. If the code matches the one stored in the EIS, the immobiliser is deactivated, the ESL (Electronic Steering Lock) is disengaged and the engine can be started. If the code does not match, the immobiliser remains active, and the engine will not start.

The EIS is a complex system that requires specialised knowledge and equipment to diagnose and repair. If the EIS is faulty, it can cause a range of issues, including the engine not starting, the central locking system not working, and the alarm not arming or disarming. In such cases, our highly experienced technicians are at hand to extensively test and repair all types of EIS and ESL failures.

Which Model Mercedes Has The EIS Module

The EIS module is factory fitted to almost all models and we’re getting units sent in right across the board, in fact Mercedes-Benz vehicles from the C-Class, E-Class, S-Class, CLS-Class, CLK-Class, CL-Class, ML-Class, GL-Class, R-Class, SL-Class, and SLK-Class are all fitted with the Electronic Ignition Switch (EIS) system. 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.

Common EIS Problems

Like any other electronic component, the EIS unit is prone to faults and failures. Here are some of the common problems people experience with the Mercedes-Benz EIS unit:

• Failed Ignition: One of the most common issues with the EIS unit is a failed ignition. This can be caused by a faulty key, a damaged EIS unit, or a problem with the wiring.
• Key Not Turning: Another common issue is when the key does not turn in the ignition. This can be caused by a worn-out key, a damaged EIS unit, or a problem with the steering lock.
• Immobiliser Failure: The EIS unit is responsible for controlling the immobiliser, which prevents the car from starting without the correct key. If the immobiliser fails, the car will not start, and the EIS unit may need to be repaired or replaced.
• Keyless Entry Failure: The EIS unit is also responsible for controlling the keyless entry system. If the keyless entry system fails, the car may not unlock or lock properly, and the EIS unit may need to be repaired or replaced.

In conclusion, the Mercedes-Benz EIS unit is a critical component of the car’s security system, and any faults or failures can cause significant problems. If you experience any of the above issues, it is essential to have your EIS unit checked by a professional.

In some cases, a failing EIS or ESL can be the result of either human error or another fault on the vehicle and 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.

Sinspeed EIS Repair Service

When it comes to a faulty EIS (Electronic Ignition Switch) unit in a Mercedes-Benz, it is often better to repair it rather than replace it with a new part. This is because the EIS unit is a complex component that is linked to other systems in the car, such as the immobiliser and keyless entry.

Replacing the EIS unit with a new one can be expensive and time-consuming, as it requires reprogramming the keys and other systems. Additionally, a new EIS unit may not be available for direct purchase and special order items can cause further significant delays in getting your vehicle back on the road.

At Sinspeed, we offer a comprehensive EIS repair service that covers all aspects of diagnosing and fixing faults with your EIS unit. Our service includes:

• Diagnosing the fault with your EIS unit: Our experienced technicians use the latest state-of-the-art technology and leading diagnostic equipment to identify the root cause of the problem with your EIS unit. We’re able to fully communicate with the unit on our test bench, power it up and simulate it as if it were operating on your vehicle, allowing us to confirm faults and identify the root cause of any failures.
• Repairing or replacing faulty components: We use genuine OE components to repair or replace any faulty parts in your EIS unit, and where possible, uprate components to eliminate any known weaknesses and ensure that it is restored to full working order.
• Recoding the EIS unit to work with your existing keys: We can recode your EIS unit to work with your existing keys, saving you the cost and hassle of having to replace them or have them reprogrammed.
• Testing the EIS unit to ensure that it is functioning correctly: After completion of the EIS Repair, we rigorously test your unit to ensure that it is functioning correctly before returning it to you.
• Lifetime warranty for complete peace of mind: We offer a lifetime warranty on all of our EIS repairs, giving you complete peace of mind that your EIS unit is in safe hands.

EIS Replacement Options

When it comes to the Mercedes EIS, it is a common failing part that can cause a lot of frustration for vehicle owners. While repairing the original part is often the best option, there are times when a replacement may be necessary.

At Sinspeed, we understand the importance of using genuine parts and repairing components whenever possible – not only does it reduce complications on the vehicle but we should all do our part to be carbon-neutral. That’s why we always recommend trying to repair the original EIS before considering a replacement. Not only is this the most cost-effective option, but it also ensures that the vehicle is using the part that was specifically designed for it.

However, there are situations where a replacement may be necessary. In these cases, we offer high-quality replacement parts that are fully compatible with the vehicle. Our team of experts can program the replacement part so that there is no need for any recoding when it is re-installed back on the vehicle. This makes the replacement process quick and easy and ensures that the vehicle is back on the road as soon as possible.

Any replacements offered will be genuine parts that meet and exceed OE specifications. This ensures that the replacement part will perform just as well as the original, and will provide reliable service for years to come. In fact, it will also be covered by the Sinspeed Lifetime Warranty for complete peace of mind.

At Sinspeed, we pride ourselves on our expertise and attention to detail when it comes to EIS repairs. Our technicians have years of experience in working with Mercedes-Benz vehicles, and we use only the latest diagnostic equipment and genuine OE components in our repairs. So if you’re experiencing issues with your EIS unit, get in touch with us today to see how we can help.

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.