Chrysler Repair: Codes 12,13,43 on 97 LHS, volt supply, coil pack

Question
Well I was on the interstate driving home and my RPM gauge started to fluxuate so I shut the car off not knowing what to do, after a few shutting the car down, I turned it back on and it ran really rough for less than a second and died.. After analyzing the engine, I tested it back to the coil, but after replacing the coil it still will not start. It seems to me that it is getting spark only sparaticaly, if I spray WD-40 into the intake (EGR Valve) it will back-fire, but after it backfires it get nothing... any help would be greatly appriciated.

Answer
Hi Carl,
The 12 code means that the battery was disconnected from the system recently, and is quite common and not relevant unless that is not the case. By recently, it means the past 50-100 key cycles.
The 13 code means that the MAP (manifold absolute pressure sensor) is not changing its reading at all and usually that means that the sensor is bad. With the sensor screwed directly into the intake manifold it should be reliably experiencing the map so it must not be responding to it, or the wires from it to the controller must be broken. You will find the MAP on the rear end of the intake manifold of the 3.3 L engine and on the side of the manifold on the 3.5 L engine. It has a 3-wire plug: black/light blue is the ground, violet/white is the 5 volt supply which should be there when the ignition is on, and dark green/red is the variable signal voltage which should be about 4.5 volts at 0 rpm and in the range of 1.5 to 2.0 volts depending upon rpm. You could probe that wire with a pin and measure the voltage between the pin and a second pin inserted in the ground wire to see if it changes when you crank the car, which it should. You can trace the wires to the engine controller:
pin 4, 6 and 1 respectivelly at the 60-way connector at the ecu. So I would suspect that the MAP problem is the reason for the no start. It would result in an improper mixture to sustain idle.
The 43 could have been due to the coil pack having a problem in one of its primaries though there again could be a problem with the wiring to the ecu. The three single color wires go to pins 17,18, and 19 of the ecu 60-pin plug and dark green/orange should have 12V when the engine is cranking that comes from the autoshutdown relay if the cam and crank sensor say that the engine is being cranked.
But check the MAP first.
You can erase the codes by disconnecting the battery for a few minutes, but of course when you recheck it there will be a recurrent 12. But then try and start it and see which codes are persistant.
Please let me know of any progress.
Roland