2000 GMC Yukon Denali with engine codes P0740, P0753, P0758, P0785, and P1860

Question

I have a 2000 GMC Denali. I have several codes that show up. P0740,P0753,P0758,P0785,P1860. The gear indicator light, the speedometer, the tach, and odometer randomly stop working also. When they do work the transmission works also. This problem comes and goes. When the vehicle has been sitting and I start it up, if the tach comes up then everything else also works. Once it is working it works fine until the vehicle is shut down. Transmission fluid was 1 qt low. Added a quart but no change. HELP

Answer 1

P0740 Torque convertor clutch circuit malfunction

P0758 Shift solenoid "B" electrical/2-3 shift solenoid circuit electrical

P0753 Shift solenoid "A" electrical 1-2 shift solenoid circuit electrical

P1860 TCC (Torque convertor clutch ) solenoid circuit open,or shorted to ground,or shorted to power

P 1860 is your concern, The reason why the TACH randomly stop is it is fused to IGN 0 which fuses the TACH ,the TCC, shift solenoid 1-2, TCC, shift solenoid 2-3. IGN 0 is also instrument cluster,Because you have P1860 your short can be coming from the TCC,The TCC is one area, the instrument cluster can have the short which affects the transmission solenoids,

Answer 2

P0740 GMC - Torque Converter Clutch Malfunction
Read more: https://www.autocodes.com/p0740_gmc.html

P0753 GMC - 1-2 Shift Solenoid Circuit Electrical
Read more: https://www.autocodes.com/p0753_gmc.html

P0758 GMC - 2-3 Shift Solenoid Circuit Electrical
Read more: https://www.autocodes.com/p0758_gmc.html

P0785 GMC - 3-2 Shift Solenoid Circuit Electrical
Read more: https://www.autocodes.com/p0785_gmc.html

P1860 GMC - TCC PWM Solenoid Circuit Electrical
Read more: https://www.autocodes.com/p1860_gmc.html