Transmission issues

is it the 2.2 or 4.3L

did you look those codes up? that might be a start~ did you check the fluid level? if high mileage might need some maintenance...fluid and filter change of the transmission~...if pretty high mileage or seen Hard duty (like a multiple horse trailer)~ these have mechanical linkages, I believe...assure the mounting points have not slipped~

Here are what the codes mean...Possible causes p1860...> - Faulty Torque Converter Clutch Pulse Width Modulation (TCC PWM) Solenoid - Torque Converter Clutch Pulse Width Modulation (TCC PWM) Solenoid harness is open or shorted - Torque Converter Clutch Pulse Width Modulation (TCC PWM) Solenoid circuit poor electrical connection When the PCM detects a continuous open, short to ground or short to power in the TCC PWM solenoid valve circuit, then DTC P1860 sets. DTC P1860 is a type B DTC. Possible symptoms - Engine Light ON (or Service Engine Soon Warning Light) P1860 Chevrolet Description The Torque Converter Clutch Pulse Width Modulation (TCC PWM) solenoid valve controls the fluid acting on the converter clutch valve. The converter clutch valve controls the TCC application and release. The solenoid attaches to the control valve body within the transmission. The solenoid receives ignition voltage through circuit 239. The Powertrain Control Module (PCM) controls the solenoid by providing a ground path on circuit 418. Current flows through the solenoid coil according to the duty cycle (percentage of ON and OFF time). The TCC PWM solenoid valve provides a smooth engagement of the torque converter clutch by operating during a duty cycle percent of ON time.....>po740..>Possible causes....> - Low transmission fluid level - Dirty transmission fluid - Faulty torque converter clutch solenoid valve - Torque converter clutch solenoid valve harness is open or shorted - Torque converter clutch solenoid valve circuit poor electrical connection When the PCM detects a continuous open, short to ground or short to power in the TCC solenoid valve circuit, then DTC P0740 sets. Possible symptoms - Engine Light ON (or Service Engine Soon Warning Light) - Transmission shift shock - Vehicle may not shift into the highest gear P0740 Chevrolet Description The Torque Converter Clutch (TCC) solenoid valve is an electrical device that is used with the torque converter clutch pulse width modulation (TCC PWM) solenoid valve in order to control TCC apply and release. The TCC solenoid valve attaches to the transmission case assembly extending into the pump cover. The Powertrain Control Module (PCM) controls the solenoid by providing the ground path. The PCM monitors the throttle position (TP) voltage, the vehicle speed and other inputs in order to determine when to energize the TCC solenoid valve.....po753...>Possible causes...> - Low transmission fluid level - Dirty transmission fluid - Faulty 1-2 Shift Solenoid valve - 1-2 Shift Solenoid valve harness or connectors - 1-2 Shift Solenoid valve circuit is open or shorted When the Powertrain Control Module (PCM) detects a continuous open, short to ground or short to power in the 1-2 SS valve circuit , then the P0753 is set. Possible symptoms - Engine Light ON (or Service Engine Soon Warning Light) - Transmission will not shift gears P0753 Chevrolet Description The 1-2 Shift Solenoid (SS) valve controls the fluid flow acting on the 1-2 and 3-4 shift valves. The 1-2 SS valve is a normally-open exhaust valve that is used with the 2-3 SS valve in order to allow four different shifting combinations. The solenoid attaches to the control valve body within the transmission....po758...Possible causes...> - Low transmission fluid level - Dirty transmission fluid - Faulty 2-3 Shift Solenoid Valve - 2-3 Shift Solenoid Valve harness or connectors - 2-3 Shift Solenoid Valve circuit is open or shorted When the Powertrain Control Module (PCM) detects a continuous open, short to ground or short to power in the 2-3 Shift Solenoid (SS) valve circuit, then DTC P0758 sets. Possible symptoms - Engine Light ON (or Service Engine Soon Warning Light) - Transmission will not shift gears P0758 Chevrolet Description The 2-3 Shift Solenoid (SS) valve controls the fluid flow acting on the 2-3 shift valves. The 2-3 SS valve is a normally-open exhaust valve that is used with the 1-2 SS valve in order to allow four different shifting combinations. The solenoid attaches to the control valve body within the transmission. The Powertrain Control Module (PCM) controls the solenoid by providing the ground path.

I have the 4.3l I have change the fluid and filter about 2 months ago and I have looked up the codes I replaced both A and B shift solenoids no change it seems like there no power to the transmission I have 3rd and 2nd gear and reverse when I manually shift but when I shift down to drive it's starts off in 3rd

hate to suggest this...but easily clean the Negative and positive ground...and the connections...lugs, connectors to assure excellent grounding....especially to the engine and chassis...there is a lug on the other end that connects to the block...unbolt and wirebrush to assure a solid connection, to the chassis, for the heart of your sensors....again, the system ground...start cleanin all the corrosion and auxilliary connections to make sure the brain gets solid power....that's my two bits...think BASIC...electronic practically NEVER fail...except when power goes BROWN...due to the number of problems am gonna have to say THE ECU...make sure it gets Solid power!~ Thanks (judge_roy)...bob_nueske