Ignition Problem on '05 W203
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Joined: Aug 2004
Posts: 631
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From: Augusta, GA
'05 SS Brillant Silver
Ignition Problem on '05 W203
Thought I had seen this one posted but couldn't find it. Found similar problems but not exactly this one.
Occasionally, will turn the key and nothing happens. Radio comes on, lights work, etc, but no start. Turn it back to off and back on and works fine. Th as happened off & on prolly for the past 5 months. Well the other day, it took my wife 4 times b4 it cranked...so you know I got an earful.
Anyone else have this, and if so, service code from dealer when they fixed it? I've been slack about taking it in, because I know the dealer will just spit back a "could not replicate problem." I'd like to be able to tell them exactly what to look for.
Occasionally, will turn the key and nothing happens. Radio comes on, lights work, etc, but no start. Turn it back to off and back on and works fine. Th as happened off & on prolly for the past 5 months. Well the other day, it took my wife 4 times b4 it cranked...so you know I got an earful.
Anyone else have this, and if so, service code from dealer when they fixed it? I've been slack about taking it in, because I know the dealer will just spit back a "could not replicate problem." I'd like to be able to tell them exactly what to look for.
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From: Toronto, Canada
2019 C300 Wagon; '75 Triumph TR6; previous: 2004 C230 6spd sold after 17 years of driving
I've experienced this everynow and then. I reported it to the dealer and of course they could not find a problem
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From: Augusta, GA
'05 SS Brillant Silver
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Joined: Jan 2005
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From: Orange County
2005 C Wagon (No snickering please!)
The part you stick the key into mounted in the dash is called the Electronic Ignition System, or EIS for short. It stores the unique identifier for the keys that are allowed to start the car.
The battery in the key can be dead, but it will still start the car. The EIS has an induction coil that sends power to the key when it is inserted in the hole. It is a two part transformer, the primary is in the EIS, and the secondary is in the Key.
The EIS then asks the key "who are you?" and the key responds with the string pattern both agreed upon when they last met. The key sends the data through the infrared port on the key. The key also receives the next data from the EIS through the infrared port. When the EIS senses that it is one of the keys allowed to start the car, it sends an "Alles Gut" signal to the front SAM that then goes to work.
I would try cleaning the window on the key, and the one in the dash. A little Windex on a soft cloth works well.
It is a very hard system to troubleshoot because the EIS connects to everything from the wipers to the speed control and many devices in between.
The battery in the key can be dead, but it will still start the car. The EIS has an induction coil that sends power to the key when it is inserted in the hole. It is a two part transformer, the primary is in the EIS, and the secondary is in the Key.
The EIS then asks the key "who are you?" and the key responds with the string pattern both agreed upon when they last met. The key sends the data through the infrared port on the key. The key also receives the next data from the EIS through the infrared port. When the EIS senses that it is one of the keys allowed to start the car, it sends an "Alles Gut" signal to the front SAM that then goes to work.
I would try cleaning the window on the key, and the one in the dash. A little Windex on a soft cloth works well.
It is a very hard system to troubleshoot because the EIS connects to everything from the wipers to the speed control and many devices in between.
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Joined: Mar 2005
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From: Southern CA
05 C230K SS
I am not aware that there is a recall, but it's good to know, because my car does it 6 or 7 times since I brought it 2 1/2 years ago. It's quite annoying, but I usually take the key out, insert it back in and the car starts just fine.
