So today I removed and inspected the TCM module and all wiring and connections on the passenger side. I also redid theground on the inner fender, and cleaned all the attachment points on the module itself. I have yet to find any questionable wiring or connectors. Everything is in very good condition. . I also pulled the FCM (gateway) module and had another look at that. There is some insulation eaten away on the outside of the unused plug, so I scrubbed that in case it was shorting. I checked the plug for power and there is 12 volts to the appropriate plug, and five volts to most of the others. I have not traced them all yet but I guess that is my next step. I also confirmed that the ground is good to the plug. I am stumped at this point.
Any new suggestions are welcome.
I would like to open the three modules up to have a look for arcing or other damage, but the cases seem quite well sealed. Would i do any harm if I pry them open?
I opened up the ECM on my 2002 CRD no problems.
Have you done a search
on this forum for U0146?
There are a few hits there...one specifically pointed to a ground point located just above the TCM.
Some of these entries are from some guy called Billwill which was my previous User ID which was suspended due to a long period of non-usage
I know that some code readers can hold up the bus so the reader needs to be disconnected while trying out the vehicle.
I have done some major electrical diagnosis on my 2002 Export CRD due to the main harness being damaged upfront from a frontal impact. I had to cut off several wires at both ends..including splices..because I was tracing some leakage to chassis.
I then replaced these wires with new ones completely.
Looking at the wiring diagrams for your 2005 KJ with the U0146 error though I do not envy your task at hand!
The wiring for this communication bus goes all over the place with plenty of splices so unless you can find a missing ground I think the next step is to find a replacement FCM module from a breaker yard and hope that fixes your problem but it could be any number of other failing components or failing wires somewhere!