Codes P0740, P0753, P0758, P0785, P2761 and P2101, Transmission?

Tiny
GMFABS
  • MEMBER
  • 2005 GMC ENVOY
  • 3.6L
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 160,000 MILES
Hello, thank you all in advance for solutions. I had several codes come up. P0740, P0753, P0758, P0785, P2761, P2101. I had 2 solenoids changed, the 2 in front of the transmission, new fluid and filter. The original problem was shifting first and second gear. It would move but very hesitant and very slow. But if I shifted manually from first second and third it ran fine. So, the solenoids got changed, and I'm still having the issue with it shifting and actually driving. The harness did not get changed nor did the other solenoids. Please help, I have no idea what else to do, neither does my mechanic. Thank you
Monday, August 21st, 2023 AT 10:28 PM

3 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,321 POSTS
With all of these code I would clear them, then turn the key on without starting the engine and re-run the cdoes, we are looking for the most prevalent code, if no codes come up start the engine then shut it off and run the codes again.

P0740: Torque Converter Clutch Solenoid Circuit

P0753: Shift Solenoid A Electrical

P0758: Shift Solenoid B Electrical

P0785: Shift/Timing Solenoid

P2761: Torque Converter Clutch Pressure Control Solenoid Control Circuit/Open

P2101: Throttle Actuator Control Motor Circuit Range/Performance

Also, is the transmission fluid burnt?
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Tuesday, August 22nd, 2023 AT 1:07 PM
Tiny
GMFABS
  • MEMBER
  • 2 POSTS
Thank you so much for your answer. I did look up all those codes. I cleared the codes with a scanner. After driving the vehicle again, the codes still pop up. I can manually shift the vehicle and it seems to work better. The biggest problem is first and second gear, those are the solenoids that I had replaced. The fluid was not burnt, but it was very dark and there were metal shavings in the pan. I'm wondering if it is possible the solenoids are defective, or can the harness be bad? Thank you again.
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Tuesday, August 22nd, 2023 AT 7:11 PM
Tiny
KEN L
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Yes, it sounds more like the harness is bad I would check the main wiring connector at the transmission and the wiring in general for damage/corrosion. Also, it could be a bad PCM.
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Thursday, August 24th, 2023 AT 10:41 AM

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