03 trailblazer tranny problem

[billygeg]

Hey Guys! I know this is a turbo buick site, If I offend anyone, I apologize..Just thought I would give you guys a shot because I know you guys are phenominal with cars! Besides, I tried to ask at a GMC trucks forum and it seems like they are all tight knit sites that the members only want to respond if your part of their click! I kow you guys here arent like that after all the help I found for my GN...Heres the deal...
My wife and I left Albany yesterday from attending a wedding. As soon as we got on the NYS thruway the truck stopped shifting into gear. My wife would press the gas and the rpm's would go up but no go..We pulled to the sholder, Shut the truck off, Then restarted. She went a few hundred feet and it did the same thing. We really needed to get off the highway so we did this for about 17 miles on the sholder! Once we were off the highway we were able to get a tow.. My wife works for advance auto and some of the guys are telling her it sounds like the shift solenoid. The engine light did come on and the code was PO757 which is the B shift solenoid stuck open I believe. My question is, before I replace this thing for nothing. Would this solenoid being bad give the symptoms I described? or do you think the tranny is shot? The ATF is dark and smells burnt and the level appeared to be too high. It was way above the cross section on the dipstick. I only bought the truck 2 months ago from a private seller and foolishly never checked the fluids when I bought it. I dont kinow if the fluid was this high when he sold it to me or if there is a problem making it appear higher than it really is. I know I never added fluid to it. If I do have to change this solenoid can anyone tell me which one it is? I know its under the tranny pan but there are a few. If anyone can explain which one it is or give advice I would really really appreciate it!
Thanks! Bill

 

[snyderjw1]

If it feels like it has 1st and 2nd and then goes into "neutral" instead of 3rd you have more than likely burned up the 3/4 clutch pack...unfortunately this is pretty common and we have seen this in trucks with very low mileage.

The computer wants 3rd, but does not get the rpm drop, so it assumes a solenoid failure...you can check the solenoid to make sure it's not broken (which can happen during a pan service) but if all looks good, and particularly since you mentioned the fluid is burnt...I'd suspect the 3/4's are gone.

From Identifix:

P0757 2-3 Shift Solenoid - No 3rd Or 4th Gear - With Automatic TransmissionPossible Causes Setting Conditions
ATF is burnt or contaminated
Transmission has an internal malfunction
Shift solenoid valve seals are damaged
Transmission has failed
Condition 1
DTC P0502, P0503, P0740, P0742, P0753, P0758, P1120, P1220, P1810 and P1860 not set; engine runtime over 5 seconds, not in Decel Fuel Cutoff, gear range is D4, TP angle more than 10%, TFT signal from 68-266ºF, system voltage from 10-18v, engine torque from 0-400 lb ft., transmission output speed over 150 rpm, 3rd gear commanded on for 1 second, and the PCM detected the estimated gear ratio was from 1.6-1.8 with the engine torque from 50-400 lb ft., conditions met for 2 seconds.
Condition 2
Engine running under the conditions listed above; 4th gear commanded "on" for one second, and the PCM detected the estimated gear ratio was from 1.8-3.3 with the engine torque from 0-400 lb ft., conditions met for 2 seconds.

This code sets in 1 Trip(s).
This code will turn on the MIL (Malfunction Indicator Lamp)