P0700 & P0875 switch d

[inkjunkie]

Have an 02 2500HD, LB7 and an Alison. Trans as rebuilt several years back by a friend, all the available updates were done to it. Has had regular fluid changes. Have an Edge CTS2, think that is the model number on the windshield and has tunes from a shop in Idaho, using EFI Live. Fluid temp was way higher then normal. Hit the sump with an infrared thermometer, gauge said 235* sump said 150*. Replaced the pressure switch. Started the truck, codes were present. Checked the connector at the back of trans, was wet with ATF. Replaced the internal harness. Also replaced the NSBU. Fired truck up, codes still there. Checked all the grounds, they are all good. Any suggestions?

 

[btfarm]

I'm assuming you cleared the codes when you finished the repairs.

 

[inkjunkie]

I'm assuming you cleared the codes when you finished the repairs.

Yes Sir...I did.

 

[inkjunkie]

Should add...when clearing the codes there is a very audible clunk from the trans.

 

[inkjunkie]

Started truck, cleared codes. Left it in park until the CEL came on. As the CEL was coming on there was a clunk in the trans. When clearing the codes there was another clunk. For the past 6 months or so every now and then when I would let go of the brake and get rolling from a stop there has been a slight thunk. Feels like if you had electric trailer brakes cranked up.
Also just checked the 4 wires from the NSBU to the TCM, all had continuity.

 

[inkjunkie]

Truck is up on stands. CEL lite is on, brakes are firmly applied. Shifting from neutral to drive the speedo jumps.

 

[btfarm]

When my LML Transmission to TCM cable connector seal failed and shorted out it also took out the TCM and acted similar to the slamming into gear you describe.

 

[inkjunkie]

Found a broken wire on the connector going into the trans.

 

[MrMarty51]

WOW, Nice find.