Random limp mode and SES codes

[TwoPedal98]

98 k1500 133k 5.7L 4x4

So the past two days I've been getting random SES light with codes P-1860 Po740 and tranny going into limp mode on start up, as random as turn truck off and turn back on and it's fine! tranny shop told me I needed to rebuild the valve body 400-600$, would like to just wait and get full rebuild like I was planning in a couple months, any cheap fixes or remedies to help me out a little bit longer? Thanks in advance!!

 

[ChrisAU]

Idk much about the electronics on a 96-98, but it sounds like a sensor connector somewhere is bad and isn't communicating on the first try.

 

[TwoPedal98]

Thanks chris! I'll see if I can find anything outta place as far as plugs and wires, this is my first two pedal truck so I don't know much about auto tranny's but I'll see what I can find, thanks again

 

[badazzbulldog]

read this link it may help http://67-72chevytrucks.com/vboard/showthread.php?p=4014866

 

[rhino]

I would check the one thing those two codes have in common.... the power wire. They get there feed from the ignition, it goes out commonly on these. Easy way to check is hook your ohm meter to the transmission fuse, see the voltage while engine off. Crank the truck, watch the voltage drop, if it goes below 10 volts, it's most likely the ignition switch under the column. You can change it, or they make a relay that changes the power source.

 

[frito-bandito]

Also check your TPS, mine makes my tranny do all kinds of weird things