Truck Help!!

[FFL8N]

First the Codes
P0500
P2509
P1755
U1403
U0121

I have ABS, Brake, and Check engine lights on. No speedo. Mileage will not change as I drive. No cruise control. I blew the fuse to my brake controller without having a trailer hooked up at the time. I was in 4 wheel low and was hunting, trying to get up a canyon and hit ice. The tires spun and my Edge Controller backlight stopped working (it has since come back on, not sure if its because I replaced the fuse for the brake controller. I know, strange) The truck was stuck in 4 wheel low and the electronic transfer case switch no longer seemed to be trying to shift as I changed its settings. The Edge was only being used as gauges at the time and was on setting of stock. I am planning on taking the Edge out completely from the system to rule it out. Anybody have a starting point for me other than getting rid of the Edge. I know that there is a lack of communications from my truck, but I don't understand why this would happen all of sudden. I have had the accessories on the truck for a few years now with no problems until now. Sounds like I need to make a trip to the dealer, just hate to do it and don't really have the money right now.

 

[FFL8N]

I had removed the bright box from the system about a year ago by the way.

 

[Prairie Dog]

I would check the speed sensor at rear end or at each wheel.

 

[p-Bar]

Ya 2nd the speed sensor on the rear end

 

[Ozymandias]

Clear the Codes and try again.

 

[FFL8N]

The first thing I did when I couldn't get it out of 4 wheel low was to remove both battery grounds for about 5 minutes to try to reset everything. I've been pulling all of my aftermarket stuff off just to get it out of the way and to rule it out. I need to pull the EGT probe to get the rest of the edge wiring out. Can anyone tell me what size cap I need for it and what the threads are. I think the threads are pipe threads, but its been so long, I don't remember now.
One other thing, when I was pulling all the wires out, there is one that run up under the steering column. I don't remember what it was for either. Its been about 5 years since I did the install.

 

[Bob4x4]

The thermocouple should be 1/8 npt,but you don't need to remove it

 

[p-Bar]

ya just unplug the wires

 

[AH64ID]

Unplugging the batteries won't clear the codes, they need to be reset with the Edge or Smarty.

 

[Ozymandias]

2x, if I have codes I write them down and then clear it with Autoenginuity.
Most of time they disappear and don't come back again.

 

[RVTRKN]

The thermocouple should be 1/8 npt,but you don't need to remove it

But be careful, it could be 1/8" British Parallel Pipe thread which has almost a strait (slightly tapered) tap and I speak from experience because I had to order the correct tap for my sensor, even with the Vendor swearing it was 1/8" NPT. But as mentioned, just unplug it, hopefully someone applied anti seizing compound to the threads when installed if you chose to remove it.