A bizarre and common problem that some Mercedes-Benz owners may encounter is not getting their vehicle to start when they attempt to start their cars. This problem happens when the key is no longer turning in the ignition. It could be by any of the following: a failing or defective key fob, a defective shifter control unit, or a failing Electronic Ignition Switch (or EIS). It can also be a Bad Electronic Steering Lock (ESL) module. Some affected Mercedes-Benz models include the E-Class, C-Class, S-Class, ML-Class, etc.
Common Causes and Symptoms
The Ignition switch (with immobilizer module) may fail after many operating cycles or user error. This problem could be a low battery or a power surge when jumpstarting the vehicle when the key is still in the ignition, causing the EIS to lose (or flash) its memory. When this occurs, replace or repair the module.
Other notable symptoms of a failing or failed Ignition switch or steering lock include:
- Intermittent functioning of the key fob
- Intermittent failure of the push start button (if equipped)
- The inability for the key fob to turn to the starting position to start the car
- Instrument cluster lights do not illuminate after you turn the key
- The key fob turns, but the vehicle will not start
- The steering lock does not release steering when you turn on the ignition
- The key fob does not rotate at all in the ignition slot.
However, there are instances where only the key fob may be faulty. In that case, if a spare is available, use it to start the vehicle and see if it works. If it does not, replace the EIS. Fixing this problem requires the services of a professional to get it right for your vehicle. At A1 Performance Auto Repair, we would ensure that this is done professionally by offering you world-class services. Give us a call and be assured of a trouble-free automotive experience.