Chrysler Repair: 2003 T&C Engine trouble: rought running, Code 1297, signal wire, battery supply

Question
I have a 2003 T&C that is just over 71000mls. The car has had regular maintenance with no problems ever - all of a sudden the engine light came on, the engine started rattling and shaking, and it sounds like there are pieces broken inside rattling around. If you start it, it runs really really rough, threatening to die. We had it towed to a shop but since we are in Germany, I am really concerned that they aren't going to be able to fix it. The only error codes we get are P1684 and P1297(we got the latter when trying to start it after the problem began). I have read a great deal about the sensors on the PT Cruiser, could this be caused by the sensors going out? The mechanic says he is going to have to take the engine apart to figure out what it is. HELP!

Answer
Hi Tracy,
The 1684 is about the battery supply to the transmission contol module having been lost sometime in the recent past. It could be an actual disconnect of the battery occured, or through some testing that happened, or a loose wire but in any case I doubt it would affect the engine running.
On the 1297, that one is very specifically pointing to the manifold absolute pressure sensor which is mounted directly to the intake manifold. It has several possible causes:
the 5V supply to the sensor may be open or grounded and that can be verified by reading the voltage on the violet/white wire with the ignition switch in the run position. The signal wire can be open or shorted to ground and that could be checked by measuring between the plug to the module (dark green/red wire) and pin 36 of the plug to the engine controller. The sensor could be loose in its mounting position.
But most likely the sensor itself is faulty and it is easy to replace (a couple of screws). It should cost less than $100 for the part itself.
I would therefor tell the mechanic to examine this MAP sensor and verify what is the status of this sensor and its circuit before doing anything else. I can't give you any opinion about the noises but if the MAP sensor signal is lost then the fuel/air mixture will be imperfect which will often cause not only rough idling but even refusal to start.
Don't authorize opening the engine until you are satisfied that the MAP code has been solved by erasing it and trying to restart the engine and having ir no longer appear. That is the first order of business.
Roland