Hi Greg. Welcome to the forum. The ignition switch and key cylinder are two separate parts. Thank Chrysler for having the sense to do that. After the switch is replaced, a roll pin is pushed in to release the old key cylinder from the old switch so it can be transferred to the new one. That can't be done without the key because simply turning it to "crank" sets the roll pin in place to retain the cylinder in the new switch. The result is you will still be using your old keys. Even if the cylinder needs to be replaced, the dealer has a kit to build the new cylinder to work with your old keys.
The switches have caused a lot of trouble in the past, particularly for people who use the heater fan on the highest setting a lot. The high current overheats the switch contacts leading to things cutting out intermittently.
As for the many computers on the vehicle, it typically IS only one or two parts that fail but there is no way to repair them other than sending them to an authorized repair center. No one else has a service manual so there is no way to know the function of each part or how to identify the defective one(s). Very often the entire board is sealed in a gooey gel to protect it from moisture and vibration. There is no easy way to remove that gel. Even if by some miracle you could figure out which part is bad, where would you go to buy a replacement? The individual parts are just not available to us. If you look at a motherboard for a personal computer, you will see the same types of components that are also impossible to buy.
The advantage to the personal computers and the computers in a car is the quality of the parts used. Tvs and vcrs do not use the same quality parts because they would be too expensive. (I was a tv repairman for 35 years). If tv grade parts were used to build a personal computer, you would be replacing the motherboard at least once per week. The quality of the parts used in cars is much higher.
Part of the reason for the outrageous cost of computer modules is that once it is installed, the software must be downloaded over the internet for the specific vehicle. GM started that BS years ago and every other manufacturer copied them. It is one of the many reasons I still drive an '88 Grand Caravan and plan on never buying another new car. Oh well. No one listens to me and my friends.
Monday, June 28th, 2010 AT 12:56 AM