Mitsubishi Repair Problems? Ask a Mechanic for Answers ASAP
I have a few issues with that (jumping to a transmission after only reading codes, the rear cat comment, etc), but lets get to that shortly.
Any chance you have the actual code numbers that they found in the system?
Hmm.Well I can tell you that there is almost nothing that the service manual recommends replacing the transmission on this model. The 40/50 transmissions are 100% serviceable, anything less than a structural/case problem can be fixed.That being said... it doesn't mean it makes fiscal sense to fix it. Any internal failure usually ends up being more than one part to replace, as the failed part usually leads to debris, and there are many parts that can not be cleaned of debris and require replacement when that happens (oil pump, converter, etc). Then when you calculate the wear and tear on the transmission for the age and start adding in friction replacements etc since it is apart.... next thing you know you have a $4000 overhaul going on, which is a hard pill to swallow particularly when brand new units with a warranty are that much, not to mention being able to find a low mile used unit for 1/4 of the price or less.
For an example, I once had an Endeavor (same transmission) come in with a loose drive nut that had backed off into the planetary gears. Straight forward fix... torque and stake the drive nut and replace the damaged planetary set right? By the time the debris was fully removed it ended up getting a pump, converter and valve body as there was so much debris in there you couldn't reassemble it like that (as the old debris in the converter if you reused it for example would end up tearing up the new pump, scoring the valve body etc), and the OD clutches were burned up pretty bad so they got swapped out as well and so on.... by the end of the overhaul with labor it was just over $7000. If it hadn't been a warranty issue, it would have made way more sense to replace the transmission with a used unit for ~$1200 and called it a day, with the whole repair bill ending up being 1/3 the amount. Of course in that instance it was a warranty job so it gets repaired by-the-book regardless of cost.
Without knowing the exact codes (and specifically in the transmission controller, not the OBD codes) it is hard to say if that is a justified repair though. I can say this transmission overall is very reliable, and in most scenarios it is considered "unusual" to have a failure... I would be suspicious that there is something less severe going on. But again, technically speaking there really isn't anything at all that requires transmission replacement, all failures on this model can be repaired it is just a matter of whether or not it makes fiscal sense to do so.
An 09 should no longer have that function.... you can check though. I'm pretty sure they dropped the flash patterns (of the N light) several years before that.
Any wiring issue to the transmission is certainly going to be any area of concern. Literally every single wire going to it will cause the transmission to malfunction if it is cut/damaged/etc.What exactly is the extent of the damage to the wiring?
Sure, you can attach them here, or if the site gives you any issues (the image uploader sometimes has issues) you can instead upload to www.imgur.com and post the links here.
Sure it could be, but you don't want to just go replacing things randomly. The two speed sensors are on the top of the transmission, you need to remove the air box/intake duct, battery and battery tray to get to them. The temp sensor is internal and requires pulling the front pan off to access, and as well is unlikely to be related.But again, the actual code numbers would be needed to make any sort of judgment like that.