I have a 2000 chrysler concorde that the engine light just popped on - the error codes are po302, po420, po340

this is code for the AMBIENT AIR TEMP SENSOR which as i understand controls the interior heating/cooling , try this link
http://www.2carpros.com/questions/chrysler-concorde-1998-chrysler-concorde-auto-temp-contro

Here is a forum all on F150 trucks, just search the error code and your year

http://www.f150forum.com/f6/error-code-p0302-cylinder-2-coil-changed-45820/

I’m happy to assist further over the phone at https://www.6ya.com/expert/robert_54ae41aaaffbab00

The easiest way to figure this out is to read the touble code that triggered the check engine light.You will probably want to clear the code after making the correction,otherwise,it colud take a lot of ignition cycles to go out on its own.A basic code scanner is about 50 bucks,which will pay for itself in one use! The battery fire probably melted a nearby wire,connector,or sensor.

Well is the battery dieing while engine is running? If you have replaced all the parts you listed and the battery dies, it is a connection problem. Check for a master buss fuse between the battery and the alternator. On some cars these may be very hidden,some not so much. If this fuse is blown then voltage can not get to the battery. Hope that helps.

What code is showed there? Send us details.

it means your car has the obd2 code problem, you need a scan tool to diagnose the code, and then delete the code, i know this tool is helpful for your car. or you can take it to the chrysler dealer, they will check for you, hope help.

It sounds like you have a problem with your security system if you mean that it won't allow you to shift out of park. BUT you should start off getting the engine error code read so you will know what the car is trying to tell you. Anytime you get a check engine light, the vehicle generates an error code.

Since you probably can't drive it, you need to rent, borrow or buy an OBDII scanner and get that code, so it gives you a clue on where to begin the troubleshooting process.

Check this diagram for...
2000 Chrysler Concorde 2.7 liter DOHC V-6 VIN "U"
or
2000 Chrysler Concorde 2.7 liter DOHC V-6 VIN "V"
or
2000 Chrysler Concorde 2.7 liter DOHC V-6 VIN "R"




Good luck (remember to rate and comment this answer).

ignition switch or chip in key faulty

P0340 is a Crankshaft Position Sensor error. It determines firing order and is most likely the cause of your problem. It's mounted near the oil filter on the engine block. Below is a picture of how it appears in your car. Best of luck.
Greg