Chrysler Repair: Voyager does not start sometimes, spark plug wires, resistance ohms

Question
QUESTION: Hello!

I have looked through your answers and I have learn how to get the codes by using the switch. Now I have some numbers but I don´t know what it means, The number is: 1 2 2 1 4 3 4 3 4 3 5 5
Can You please tell me? I am from Sweden so please use a simple language when you answer.

Many thanks!
Regards Ing-Mari

ANSWER: Hi Ing-Mari,
The important codes are 12,21,43; the multiple 43's are not particularly relevant, nor is the 55 which means 'end of readout'.
The 12 code means the battery was disconnected from the car or from the engine controller sometime in the recent past (50-100 attempts to start). Unless you have not knowingly disconnected the battery this can be ignored. If you haven't disconnected it, then it could be a intermittent 'open' in one of the contacts in the ignition switch such that the battery voltage is not  being applies to the engine controller. Let me know if that is the case.
The 21 means the one of the oxygen sensors (mounted on the exhaust manifold, looks like a spark plug) is not responding normally. Usually it is a worn out sensor but it might be a broken wire at the sensor.
The 43 means that there is a problem in the primary coil wiring to one or more of the three circuits of the ignition coil pack (where the spark for the spark plug is generated). This might be due to a wiring intermittent or due to a wearing out of the coil pack. The coil pack is where the spark plug wires are attached and it has a single 4-wire supply plug and if you will notice which pin of the plug receives the dark green/orange wire, then that pin would be the one to measure the electrical resistance (ohms) between it and each of the other three pins of the socket. The resistance should be in the range of 0.6 to 0.9 ohms on each of those measurements, using an ohm-meter.
If the readings are not in that range, the coil pack should be replaced. I can tell you the detailed wiring connections for the four wires between the plug and the engine controller, but I need to know the year/engine size to give you the details.
So let me know what you find and the specifics of the year/engine and we can go on from there.
Roland

---------- FOLLOW-UP ----------

QUESTION: Hello again!
The car is a Chrysler grand Voyager -97, 3,3. We have had the battery disconnected because we have problem with the larm that won´t work properly. So that´s ok.
We have also problem with the oxygen sensor that we had to clean and put back. I think we will need to replace that with a new one. So much of what you have told me make lot of sense.
If you can tell me more I will be very greatful. We are taking it to the workshop on friday but they can perhaps need some help from us. And it will be much easier to fix it. And it won´t cost us too much.

Thanks for your help!
Regards Ing-Mari

Answer
Hi Ing-Mari,
The 4-pin plug at the coil pack has a dark green/orange wire that carries 12 to all three spark coil primary windings, for about 1 second when you first turn the ignition switch to run and then again when you start cranking the starter motor and of course when the engine run.  The other three wires are each at the other ends of the 3 primary coils and those wires oscillate between 12V and ground in synchrony with the engine rotation which cause the spark voltages on the secondary coil windings. The gray/red wire goes to pin 11, the dark blue/tan to pin 3 and the red/yellow to pin 2 at the engine controller plugs.
I am uncertain why it won't start sometimes unless you aren't getting spark when that occurs so check that when it won't start. An alternative would be that the exhaust gas reciculation valve is sticking slightly ajar at that moment, which leans out the mixture too much. Here is how to check that out:
The valve is located near the throttle body air intake at the end of the engine, mounted in pipe that recirculates exhaust gas from the rear cylider bank exhaust pipe back around to the intake manifold. The exhaust gases have some fumes that can plate out a crud on the valve stem and thus keep it from closing tight when you are at idle. That makes for a too lean mixture so the engine stalls or is hard to start. The valve proper is mounted horizontally with the stem visible in a space between the body of the valve mounted on the pipe and the round top of the valve which is flanged and so if you look carefully you will see a metal rod (stem of the valve) with a slot around its circumference. You can take the tip of flat blade screwdriver and insert it in the slot and then lever the valve back and forth to check if it is moving freely (against spring action in one direction) or not. If it doesn't seem to close easily with the help of the built-in spring, then I would spray the base of the stem with solvent from a pressure can (such as WD-40 or carb cleaner) while moving the stem back and forth.  Then see if that solves the issue.
I don't believe the oxygen sensor would relate to difficult cold starting as it doesn't come into play until the engine is warmed up, but in any case getting it replaced if necessary would help performance and economy. Difficult warm starting could either be the sensor or the egr valve.