Ok thanks for the reply! I was expecting a code and wanted to validate it since you indicated in post #1 getting code p1887. How did you get that code? I am preparing my gear to get this job started over the weekend. I managed to take close videos and pictures of the wires entering the unit but I can't see any problem. I will first try to lower the diff to have a clear view before removing it all. Again thanks for your advices.i don't think you'll get an obd code with this problem as it is not engine related. I'd say try to lower the front of the diff to see if the wires seems so start to cut, they usually cut right where they enter the diff. They start to corrode first.
Ok here is the update on my problem. I did repair it. Huge thanks to puma for starting this thread and Mixamillian for the youtube video. Everything went pretty well other than the fact that 4 bolts out of 8 snapped on me while removing the coupling unit from the diff! So I'd say if you plan on doing this repair, remove the drive shaft, remove the coupling unit brackets, lower the diff while supporting it with a jack to allow it to lean torward the ground (careful not to strecth too much and damage the diff cable here). That will give you the chance to shoot PBBlaster from behind the bolt and let it penetrate over night.
If you feel too much resistance while removing the bolts you could still use some heat on the housing around the bolts and it should come off.
I was finally able to remove the snapped bolt with a lot of heat and good vice grips (luckily they were sticking out long enough!)
So in the end, I'm very happy that I was able to repair this car that I like very much. Too bad I am now going to sell it since I bought a truck which fits more my needs these days.
I am not sure about the problem you have with the transmission but I had a weird shift behavior with the transmission on my 2013. It happened when cold at low speed and it was solved when I brought it to the dealer for a partial transmission fluid flush. I told them about the weird shift behavior and they told me they would try a software update...I was not sure about the success but it did solve my problem! Again, not sure about your problem but maybe you could try.Good to know you could do the repair. I just gave mine to my son and reminded him its only a Front Wheel drive truck now I had the water pump replaced 2 yrs ago so the engine is good. Luckily a mechanic friend did it for 1/2 the cost of a shop. The only thing left to fail is the transmission, as we get an occasional shudder under low load in 3rd,4th gear changes.
MatNic, if you have the wires corroded, the 4wd will not engage. If you can find snow (unseen this winter here!) it is easy to test if it engages or not. If you plan on doing this fix, I recommend you soak these bolts and use heat. Ask how I know!Sorry to bring up an old thread. Didn't want to start a new thread since this has been brought up before. this is a new-to-us vehicle (2012 CX-9 Touring) and after getting one of the rear differential seals replaced, the 4wd light is now coming on once I turn on the vehicle and start moving more than a couple mph. If it is the wires being corroded and needing this fix, does this mean the 4wd isn't engaging anymore and the traction control isn't working anymore and this fix needs to be done in order to have 4wd again, or is it just an warning light and the 4wd is still functioning? Can an old-school electrical tape over the light fix be done (per my father-in-law)?