Slightly turn the unit and press in the tabs on the electrical connections (yellow arrows) and separate the connections from the module. If you have an automatic transmission you will need to remove the lock out cable.Turn the unit so you have access to the cable on the top.Squeeze in the two clips (red arrows) and slide the cable forward
It could also be the EIS (electronic ignition switch), but then I'd suspect other things wouldn't be working properly. A common cause of electrical gremlins is low voltage. Check the battery before starting - it should be around 12.5v. During start it shouldn't drop below 11v, and after start, it should be around 14v.
After sitting for 20 or 30 minutes the car would start right up and run good. This symptom is common with electronic modules and ignition coils where something inside shorts out after the unit heats up either from being on or from heat absorbed from the engine. After a while my car failed to start even with the engine cold (no spark), then out
The ignition switch on your Mercedes is coded to the vehicle, so you will have to reprogram the system for the computer to recognize it. The switch itself is easy to remove but you must first remove the steering wheel, steering column tube module and the trim around the gauge cluster.
The ignition switch going bad is a known problem with Mercedes-Benz vehicles. The ignition switch is what allows you to turn the key in the ignition and start your car. The ignition switch is connected to the battery and starter motor through two wires that allow current flow from the battery to power up your car’s electrical system. Your
To prevent that problem, the ignition switch system has logic in it so that if the vehicle battery is too low, it won;t even attempt the infrared handshake and thus the switch won't be unlocked. SO, yes, if you vehicle battery is dead or dying, you might not even be able to turn the key in the ignition switch. - Rodney.
Get in car and turn ignition switch to its first position (ie engine not running) Push the gas pedal right down to the floor and hold for 5 seconds. Turn the ignition off then release the pedal. Now sit tight for 2 minutes,do open a door,turn on a light or anything. That according to some should do it.Again,I wouldn't bother.It even works through the ignition, imagine that! So, my simple mind thinks the problem must have been the head unit. BTW, the install was very easy and B**t B*y was the worst for buying the Alpine and the satellite radio tuner, etc. It took two trips to get that right but the local shop had no problems.:thumbsup: 2009 W204 c class ignition problem. I just wanted to get some opinions on this continuing problem I have been getting with my C220 CDI. Ever since it has been new (MY2009) it has occasionally failed to start. This is characterized by all the electronics turning on (radio,lights etc) but the starter motor failing to crank, with absolutely no Replace the battery in the key fob or consider having a new key programmed for your vehicle. If the spare key doesn’t work, further diagnosis will be required to identify the ignition switch issue. Remember to follow these steps to efficiently troubleshoot your Mercedes ignition switch problems. btDQ.
mercedes c300 ignition switch problems
