9400 VSS code 242

hey guys, having an issue that started today. truck was running fine and then felt like I was letting my foot of the pedal, stuttering. it didn't do it all the time, but enough to scare the hell out of me. I stopped at the pit and shut the truck off, flipped the diagnostic switch and it flashed a code. I counted the flashes and found code 242 "Vehicle Speed Sensor (VSS) circuit".

weird thing is, my speed sensor wiring on the tail shaft has been cut since I got the truck nearly 8 years ago. speedo/tach doesn't work, but never bothered me much.

I pulled the sensor out the shaft and the magnetic part is coming apart and had metal pieces stuck to it. could this be the issue? idk why all of a sudden I would get that code. I called the dealer for a replacement and they said there is only sensor for the speedo AND tach, and it's part number 1669290c91. $160 new. I'm heading into Houston in the morning to grab a new aftermarket one. guy said they didn't have an exact match but they have one that serves both as speedo and tach., just bring my old one to match the threads. my main problem is solving this VSS code, but maybe I can knock out both problems and actually get the speedo working! finding out which wires goes to what is another can of worms

*edit*
I wanted to add. a few weeks ago my truck was super low on coolant due to my radiator leaking. it threw a code: low coolant engine shut down mode, so I'm assuming it went into limp mode and was doing the exact same thing as now. could a code 242 cause the truck to go into a limp mode like that?

 

this is what it looked like. any inputs?

 

hmm, well I slapped in a new speed sensor but didn't connect the wires. ran it all week and did not see the problem or code come back. do you think maybe the harness I seen laying on the transmission could've been grounding out? one set had bare ends for some reason (no plugs) and one of the 2 wires had 12 volts with key on. I snipped the ends and zip tied them up.

it's just odd to finally see that code after all these years. I've done the diagnostic check plenty of times this code has never showed up.

heavyd I know you help a ton of people, probably won't remember me asking about my speedo/tach years ago when I first got this truck! maybe wiring up the sensor to actually work will rule out having this issue again, if I can figure out these wires I found back there

 

good point I'll run it for a little bit and see what happens. so far so good. after your help with this sensor years ago, I found a schematic book for my truck, inside of it I found the page you had posted that showed the diagram. but for some reason I don't see the wiring colors matching up with mine... plus it's a little hard for me to follow im terrible with wiring lol