Codes again- shut truck down- all are transmission related.. WHY?

2000 n-14 & autoshift 10 spd. 15 yr old truck with 981K on it. ( SO 65K a year avg on truck- not a lot by industry standards.)

got codes again last week, shut the truck down on the side of the highway,- would not shift at all- then would not shift from 5th to 6th and higher. I tested the range/ shift cylinder, per the book, all test out fine- no air leaks, air contamination, etc.

It was a sensor problem again. I was able to work thru it, and reset everything, and get her home. long story short, been having problems with the 1 gen auto shift sensors and related "hardware". Started in November of '14. the x-y shifter was replaced in 2001 & again in 2010, the shift tower computer, the trans ECM, wiring harness, and again, all the sensors on the transmission were replaced along the way..

Anyone with experience with that transmission have any clue as to why those sensors and related keep failing? is it simply getting old and time to replace parts? has been a constant known problem?

I know a lot of people don't like the autoshift trans, and I understand why,..........so please NO "hate" reply's- much appreciated.

 

Thanks for the reply's.. we will keep digging to find the problem,

I worked on the truck all day, yesterday. truck started fine, then shut off about 2 minutes later, did this 2x then truck wont start at all.. all codes say Datalink failure, datalink irregular, or abnormal.?? datalink at transmission failed, or not identifiable. we checked all the connectors. found nothing, we have cleaned all the grounds on the truck, at the starter, engine block, cab, and chassis. the batteries are all good, and terminals clean.

here are the codes.... 130 231 2 SID and 130 231 11 SID
these are transmission related... and started AFTER we replaced the main shaft speed sensor??

 

I finally found the problem yesterday after taking the entire wiring harness off and apart from the transmission- testing continuity on all the wires... I thought that the "High" data wire had a break in the line in the harness specifically for the transmission. however it tested out fine afterwards. the J1939 Data link cable itself, (AKA CAN-bus ) as it crosses over the transmission bell housing, behind the engine, was zip tied to the same bracket as the transmission cooler lines. evidently the "cooler" lines to the transmission was hot enough that it actually melted the outer shell, and inner foil "shield" of the datalink wire, grounding out the datalink "Drain" wire to the truck. we were able to fix the wire, and shielding, then taped up the new shield, and then installed black wire loom over that. I also ran the datalink wire to a different bracket, away from the trans cooler lines, and the exhaust pipe.

there is information online on specifically how to test the datalink for proper resistance and continuity. the 98-2004 vnls are supposed to have 120 ohms of resistance between pins A &B, with all "nodes"- IE computers- disconnected from the J1939 datalink wires, and terminal resistors at each end of the j1939 datalink in place. each wire tested continuity thru the entire cable should be close to 000 on the multimeter. the j1939 datalink is the green& yellow wires, with a bare "drain wire" shielded and wrapped in a heavy plastic coating, the connectors are the grey in color triangle shaped connectors- 3 pin. if those wire do not read correctly using a digital multimeter- obviously something is wrong.. start looking for it. with my issue and the transmission, I looked there first, and found the datalink wire leading to the transmission had grounded out to the truck.

I hope that this may help someone else out along the way... do a internet search for datalink testing with a multimeter... you should find the same info I found that helped me out...