when I put it in D look like it start in 2, but if I move it manually to 1 it works fine. I changed filter and fluid but problem still there. I went to autozone and they gave me these codes:
-. P0753, 1-2 shift solenoid valve performance
-. P0785, Transmission 3-2 shift solenoid
-. P1860, TCC PWM solenoid electrical fault
-. P0758, 2-3 shift solenoid valve performance
-. P0740, Torque Converter clutch (TCC) enable circuit

I read in another forum that cause could be the ignition switch because on blazers 97 it is a common problem on some of the codes causes, http://www.automotivehelper.com/topic633087.htm

If I have to replace the solenoid I wanna know where it is located and the procedure to change it.

I have blazer 97 2wd.

 

Does it shift normally from 2nd to 3rd and from 3rd to 4th? If 3rd gear is also not working correctly then you may have a broken sun shell in the tranny.
You gotta drop the pan to get to the solenoids.

 

Have a look through the following posted trouble code sheets. Try to see what is common between the codes including wiring, sensors, etc.

P0740 - Torque Converter Clutch Circuit
P0753 - Shift Solenoid A Electrical
P0758 - Shift Solenoid B Electrical
P0785 - Shift Timing Solenoid
P1860 - TCC PWM Solenoid Circuit

It is possible that the ignition switch is the source of the problem, but a little detective work will help you narrow it down.

 

I just realize that it start on 3rd not on 2nd like I said. it does fine from 3rd to 4th.

I will check the posted trouble code sheets as suggested for swartlkk. I just wanna add that the ignition switch is not working right so anyway I will have to change it.

all of them codes have in common that receives ignition voltage through circuit 1020. So it is possible that like the swith is no working fine is causing this trouble.

 

Be sure and let us know if the ignition switch fixes your problem.

 

I have found in a harness attached to the shifted that 2 cables pink and yellow are desconected but I don't in what hole put them. I attached a pic.

1 2 3
4 5 6

I see in this other picture that belong to a 95 S10 Blazer 4x4 that yellow is in position 4 and pink in position 3, is that the right one?

 

99 s-10 blazer Tranmission does fine when cold, but once it warms up it doesn't want to pull,kind of like the problem you mentioned. Have a code p0758 come up. Got the part to replace, but it looks like the part for code p0785 on diagram I have. I need to know where this 0758 part is located and if it is necessary to drop the valve body to replace it.

 

I have a 99 and sometimes when i go froma stop it seems like it dosent wana catch gear. The motor makes noise like it wants to go but its like Im in N. But once it shifts to 2nd then I dont have a problem.

Can anyone let me know why it dose this?