Transmission does not shift

Good afternoon.
It does sound like you have a vacuum leak. Check along where the head meets the manifold. Remove the oil fill cap and see if you feel pressure pushing out or vacuum.

As far as the transmission, the TPS sensor on the throttle body is the critical sensor for transmission shift points. Check the voltage at idle. It should be.5 volts. Then as the pedal is pushed, the voltage should rise to around 4.8 volts. Do this with key on engine off.

Roy

Good evening

Is the check engine light on?

The throttle position sensor on the throttle body is what controls the shifting of the transmission. It monitors the voltage and based on that the PCM sends a command to the shift solenoids to open and close.

Roy

Okay, first you need to have the codes read. You can take it to a parts store and they will read it for free.
Then once we know the code, we need to look at the possibilities and follow a flow chart to determine the failure. Codes never identify bad parts, just failed systems.

Roy

740 code

Circuit 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 TCC solenoid valve receives ignition voltage through the OFF/ON/START voltage circuit. The powertrain control module (PCM) controls the solenoid by providing the ground path on the TCC solenoid valve control circuit. The PCM monitors the throttle position sensor voltage, the vehicle speed, and other inputs in order to determine when to energize the TCC solenoid valve.
When the PCM detects a continuous open, short to ground or short to power in the TCC solenoid valve circuit, then DTC P0740 sets. DTC P0740 is a type B DTC.

Conditions for Running the DTC
The system voltage is 10 - 18 volts.
The engine speed is greater than 450 RPM for 5 seconds.
The engine is not in fuel cutoff.

Conditions for Setting the DTC
DTC P0740 sets if one of the following conditions occurs for 5 seconds:
Condition 1
The PCM commands the solenoid ON and the voltage feedback remains high, B+.
Condition 2
The PCM commands the solenoid OFF and the voltage feedback remains low, 0 volt.

Action Taken When the DTC Sets
The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in, which the Conditions for Setting the DTC are met.
The PCM inhibits TCC engagement.
The PCM inhibits 4th gear if the transmission is in hot mode.
The PCM freezes shift adapts from being updated.
The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.
The PCM stores DTC P0740 in PCM history during the second consecutive trip in, which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC
The PCM turns OFF the MIL during the third consecutive trip in, which the diagnostic test runs and passes.
A scan tool can clear the MIL/DTC.
The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids
With the TCC engaged, the TCC slip speed should be -20 to +50 RPM.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
4. This step tests for voltage to the solenoid.
5. This step tests the ability of the PCM and wiring to control the ground circuit.
7. This step tests the resistance of the TCC solenoid valve and the automatic transmission (AT) wiring harness assembly.

785 code

Circuit Description
The 3-2 shift solenoid (SS) valve assembly is a normally-closed, 3-port, on/off device that controls the 3-2 downshift. The solenoid attaches to the control valve body within the transmission. The solenoid receives ignition voltage through the OFF/ON/START voltage circuit. The powertrain control module (PCM) controls the solenoid by providing a ground path on the 3-2 shift solenoid valve control circuit. During a 3-2 downshift, the 2-4 band applies as the 3-4 clutch releases. The PCM varies the timing between the 3-4 clutch release and the 2-4 band apply, depending on the vehicle speed and the throttle position.
When the PCM detects a continuous open, short to ground or short to power in the 3-2 SS valve assembly circuit, then DTC P0785 sets. DTC P0785 is a type B DTC.

Conditions for Running the DTC
The system voltage is 10 - 18 volts.
The engine speed is greater than 450 RPM for 5 seconds. The engine is not in fuel cutoff.

Conditions for Setting the DTC
DTC P0785 sets if one of the following conditions occurs for 5 seconds:
Condition 1
The PCM commands the solenoid ON and the voltage feedback remains high, B+.
Condition 2
The PCM commands the solenoid OFF and the voltage feedback remains low, 0 volts.

Action Taken When the DTC Sets
The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in, which the Conditions for Setting the DTC are met.
The PCM commands a soft landing to third gear.
The PCM commands maximum line pressure.
The PCM inhibits TCC engagement.
The PCM inhibits 4th gear if the transmission is in hot mode.
The PCM freezes shift adapts from being updated.
The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.
The PCM stores DTC P0785 in PCM history during the second consecutive trip in, which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC
The PCM turns OFF the MIL during the third consecutive trip in, which the diagnostic test runs and passes.
A scan tool can clear the MIL/DTC.
The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
The PCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is OFF long enough in order to power down the PCM.

Test Description
The item numbers below refer to the step numbers on the diagnostic table.
4. This step tests the ability of the PCM to control the solenoid.
5. This step tests for voltage to the solenoid.
6. This step tests the ability of the PCM and the wiring to control the ground circuit.
8. This step measures the resistance of the automatic transmission (AT) wiring harness assembly and the 3-2 SS valve assembly.

1860 code
Circuit 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 the OFF/ON/START voltage circuit. The powertrain control module (PCM) controls the solenoid by providing a ground path on the TCC PWM solenoid valve control circuit. 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 TCC by operating during a duty cycle percent of ON time. 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.

Conditions for Running the DTC
The system voltage is 10 - 18 volts.
The engine speed is greater than 450 RPM for 5 seconds.
The engine is not in fuel cutoff.
The PCM commands first gear.
The TCC duty cycle is less than 10 percent or greater than 90 percent.

Conditions for Setting the DTC
DTC P1860 sets if one of the following conditions occurs for 5 seconds:
Condition 1
The PCM commands the solenoid ON, 90 percent, and the voltage feedback remains high, B+.
Condition 2
The PCM commands the solenoid OFF, 0 percent, and the voltage feedback remains low, 0 volt.

Action Taken When the DTC Sets
The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in, which the Conditions for Setting the DTC are met.
The PCM inhibits TCC engagement.
The PCM inhibits 4th gear if the transmission is in hot mode.
The PCM freezes shift adapts from being updated.
The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.
The PCM stores DTC P1860 in PCM history during the second consecutive trip in, which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC
The PCM turns OFF the MIL during the third consecutive trip in, which the diagnostic test runs and passes.
A scan tool can clear the MIL/DTC.
The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
The PCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is OFF long enough in order to power down the PCM.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
4. This step tests for voltage to the solenoid.
5. This step tests the ability of the PCM and wiring to control the ground circuit.
7. This step tests the resistance of the TCC PWM solenoid valve and the automatic transmission (AT) wiring harness assembly.

Do you have any check engine lights on? if so this guide can help us. also when you did the repair did you get the seals in correctly for the servo and drums? Check out the diagrams below to help reinstall the seals.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

and

https://www.2carpros.com/articles/automatic-transmission-problems

Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.

Okay, all three codes are related to wiring harness issues as they all are saying the PCM is seeing high voltage on the returns from the solenoids. The most likely issue here is a short in the harness. The harness in the pan is common. It is submerged in fluid and over the years it gets into the wiring and shorts out.

Since you replaced all the solenoids, the only thing left is the wiring harness.

You will need to drop the pan again and check the harness closely for any breaks or melted wires.

Roy

Even though it doesn't have a check engine light it could still have a code. Let me know if the speed sensor fixes it it.

Yes, they are a simple. 12 volt ground and power you should be able to feel a click when the circuit is completed. Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.