YES!
Those switches are known to go bad via leaking. The PS fluid wicks into the harness traveling around causing all sorts of electrical grief.
Good catch!!

Don

 

We're hoping we don't need to replace the entire wiring harness that goes to that bundle of wires into that connector to the PCM from the power steering switch that failed. I ordered the power steering switch, the plan is to replace the switch, and use an automotive electronics cleaner spray on the connector that goes to that power steering switch, and also the connector that goes to the PCM. I'm thinking it be best if we remove the PCM, and open it up if we can safely to also spray electronics cleaner in there too, and also to remove any power steering fluid, should any of it pooled inside of the PCM housing.
What a mess! I suppose worse case, is we need to replace the PCM and wiring harness. This explains why we got so many inconsistent results with resetting connectors and the battery, etc.

 

Fingers crossed it has not gotten that far along. We have had folks report of it getting into the o2 sensors and ruining them. Keep us posted.

Don

 

Finally was able to work on the Durango again today. We disconnected the battery, and replaced the bad power steering pressure sensor. I also disconnected the power steering fluid soaked PCM connector and of course the connector that went to the replaced power steering pressure sensor and used electronic contact cleaner on them both before connecting everything back together and started it up and test drove it, the P0601 computer code came back quickly but the performance during the test drive was great. We shut the vehicle down, and I repeated the cleaning of the same connectors with the battery disconnected and on the next startup and test drive, the P0601 code went away and the P0204 injector circuit open cylinder 4 code came back and is currently the only code and the poor performance returned on the test drive. I repeated cleaning the wire harnesses with contact cleaner and the P0204 code remains.
So in short, we replaced the bad power steering pressure sensor which I believe was the culprit that started this madness and the P0601 code has gone and P0204 code returned and currently remains. My dad is going to drive it for a week and we plan on cleaning the harnesses again that were affected next weekend if our schedule allows.
I welcome any ideas/feedback!

 

Talked to my dad today, he's been driving the Durango for about a week since we last worked on it. He says it will be good about 70% of the time now. Some trips it runs as it should, but some of the time it still runs rough with poor MPG. He still has the CEL, which I presume is still the P0204.

Tomorrow when I'm at my parent's house I plan on unplugging the PCM and power steering pressure sensor and hitting them with the electronics cleaning spray again.

Anything else I should do or check? If the P0204 comes back, I'm tempted to swap the injector from that cylinder with another one to see if the code follows that injector. Not sure how hard of a job that is.

 

Hi Alex:
Congrats on all of the progress. Moving that injector around to see if the code follows is a good plan IMO.
If so, I'd throw in a new one and see if that cures it.

Don

 

Hi Don, thank you!
We made further progress today on my dad's Durango. I removed the PCM connector that was soaked in PS fluid before, and it was dry this time but I hit it with electronics cleaner again, and I also pulled the wire harness connector from the injector for cylinder number 4 and hit it and the injector's contacts with the electronic cleaner spray. I did the same with the power steering pressure switch connector where the issue originated before replacing that sensor. Got everything put together again, and on first engine start and test drive there were no codes and it performed well! When we shut it down and started her back up, it ran fine but one code came back, and that was P0601. So as of now, the P0204 is gone. As long as the performance stays good, we are letting the P0601 code remain, as it has had for years with no poor performance. My dad is going to run it again all week and I'm going to check codes again next weekend to see if any go away/return.

 

An update, my dad has been driving the Durango for another week, and he said it only performed poorly once in several days. I re-scanned the vehicle and got two codes, the P0601, and the P0204 returned. Since it's working most of the time, we're leaving it for now. We talked about possibly trying another PCM from a junk yard from a like model.

 

Alex:
If you go PCM shopping, be sure that the donor D matches yours regarding the alarm system. If yours has it, the donor PCM needs to have it also. If not, then the donor also should not.

Keep us posted.

Don

 

Hi Don,
Will do! Thanks for the insight. My dad's Durango indeed has the alarm and is also a 4x4 with the 4.7 V8.
It could be a while before we get around to it. Always fun going to the junk yard though. There's always more odds and ends to pick from vehicles.
Thank you,
Alex