Chrysler Repair: Car jerking., chrysler sebring lxi, 1997 chrysler sebring lxi

Question
Hi
I recently got a 1997 Chrysler Sebring LXI.(81Kmiles).
I soon noticed slight jerking when slowing down to a stop light and sometimes even when at a full stop with the brake pedal all the way down with the car running.
I have also noticed some slight jerking when accelerating up on a highway to normal speeds of about 55-60 Mph.
I am the second owner and havent repaired anything and there for dont know the history.
If you can help in anyway it would be greatly appreciated.  

Answer
Hi Maria,
That might be the symptom of a misfiring of one of the cylinders. But the cause of it has to be determined. Fortunately modern cars have some ability to tell you what is wrong with then in the form of coded fault messages or 'fault codes' that are stored in their engine controller memory.
It may be possible for you to ask the engine controller whether it has observed any failures in the control systems that are stored as codes in its memory. The most useful thing to do would be to try to get the fault codes that may stored in the engine controller memory to readout. Try using the ignition key: turn it "on-off-on-off-on" and leave it "on" (doing this quickly, no longer than 5 seconds). By "on" I mean just the normal position when the engine is running, not the cranking position. The 'check engine'light will remain on when you leave the key in the "on" position with the engine still not running. But then watch the 'check engine' light to begin flashing, then pause, flashing, pause, etc. Count the number of flashes before each pause and keep track of the numbers. Repeat the readout and verify the counts are correct. Then group them in pairs in the order that they came out, thus forming two digit numbers. You may notice that the pause is shorter between the digits of a given number, and longer between the numbers themselves. Then send me a 'follow-up' question telling me the results of your readout. By the way, 55 will be the last number (two groups of 5 flashes each) and that is the code for "end of readout".
I have the troubleshooting manual for several engines and we can look up the possibilities of what is wrong based upon what fault codes you show. When you write back tell me what engine is in the Sebring that you are driving. It will be described on the underhood sticker, or etched into the valve cover of the engine itself.  
But then you need to get specific info for what exactly might be the diagnostic tests or parts to replace to complete the repair. If this approach doesn't produce fault codes at all*, not even a 55, then you will have to go to a good tune-up shop where they have a more sophisticated code reader in order see if there are any codes. You should be able to get a readout for under $50. Just get the exact numbers of the fault codes and write back.
So those are some ideas for you to consider. Let me know what happens and how I might be of help.
Roland
*Right around 96-97 the engine controller technology was changing to a new version which eliminated the self-readout opportunity, so that is why you may not get any flashing of the check engine light in your '97. But it is worth a try.