Both those codes you have point to the governor pressure but is it a sensor problem or a mechanical problem?

P1757: The requested pressure and the actual pressure are not within a tolerance band for the Governor Control System which is used to regulate governor pressure to control shifts for 1st, 2nd, and 3rd gear (Zero Pressure Malfunction)
P1762: The Governor Pressure Sensor input is greater than a calibration limit or is less than a calibration limit for 3 consecutive park/neutral calibrations.

The transmission temp light usually indicates the torque converter lockup clutch has failed. If it slips, the fluid gets hotter than normal.

Pulling a line off the transmission won't tell you if the pressures in the valve body are good. As magnethead said take it to a reputable shop. I wouldn't even spend the money on the fluid and filter. Get it diagnosed first or you might be wasting your time and money.

It should be a 42RE.

 

Thanks for the information. I have been looking around for a trans shop but the only thing close is the stealership.
Thanks for everyone's advice

 

That's not always the worst thing. They'll have the proper tools to diagnose the transmission. Hopefully it's minor.

Remember, you have options. You can always put in a boneyard transmission if you can't afford to get this one fixed or replaced at the dealer.

 

where are you located? If you call around to various local race shops, they can be an easy link to people that work out of the garage at night or something. We have 3 of those kinds of people out here, 2 have dedicated shops and 1 does it from his house, just making extra money here and there.

 

I ended up replacing it with a transmission from a boneyard. But, this "new" transmission has some problems too. I'll post more info later.
Thanks for everyone's help