The modulator valve is attached to the intake manifold with a vacuum line . It senses intake manifold vacuum and shifts the transmission accordingly: When you press down on the gas pedal, the throttle plate opens and the vacuum is reduced.
What are the symptoms of a bad transmission modulator?
- A whistling sound (from a leaking diaphragm)
- White smoke coming out of the exhaust (from a leaking diaphragm)
- Early or late shifting.
- Hard shifts (usually causing the car to jerk)
- A rough idle.
What is the modulator valve?
What is a modulator valve? A modulator valve is found in automatic transmissions to shift gears depending upon the load on the engine . Its vacuum line is attached to the intake which measures the amount of vacuum in the system. When the gas pedal is pushed, the throttle plate opens and the vacuum is released.
How much is a modulator valve?
Depending on the make and model of your vehicle, the cost of the replacement modulator will be around $30 to $80 . The labor costs should only be about $50 to $80 because it doesn’t take that long to replace it.
How do you adjust a transmission modulator?
Remove the vacuum line from the end of the vacuum modulator. Use a small slotted screwdriver to turn the adjuster that is located inside of the vacuum fitting. Turn the adjuster clockwise for earlier shifts and counterclockwise for later shifts. Make small adjustments of 1/8 to 1/4 turn at a time.
What are the signs your transmission is going out?
- Refusal to Switch Gears. If your vehicle refuses or struggles to change gears, you’re more than likely facing a problem with your transmission system. ...
- Burning Smell. ...
- Neutral Noises. ...
- Slipping Gears. ...
- Dragging Clutch. ...
- Leaking Fluid. ...
- Check Engine Light. ...
- Grinding or Shaking.
How do you reset Transmission Control Module?
- Step 1: Turning Key Position. Before resetting the transmission control module, it is necessary to check the key position. ...
- Step 2: Press gas pedal. ...
- Step 3: Keep Waiting. ...
- Step 4: Turning the Key Off. ...
- Step 5: Releasing Gas Pedal. ...
- Step 6: Wait Again. ...
- Step 7: Ready.
What is the purpose of a transmission modulator valve?
The modulator valve is attached to the intake manifold with a vacuum line. It senses intake manifold vacuum and shifts the transmission accordingly : When you press down on the gas pedal, the throttle plate opens and the vacuum is reduced. The modulator valve will cause the transmission to downshift.
Can a vacuum leak cause shifting problems?
A vacuum leak will cause the engine performance to suffer, causing load and throttle position issues which could affect transmission shifting.
What is the purpose of a vacuum modulator?
Vacuum Modulator is an engine load sensing device that converts engine vacuum into a transmission valve body input .
How much does a transmission modulator cost?
How Much Does a New Transmission Control Module Cost? A replacement transmission control module can cost you anywhere between $100 and $400 . Expect to spend around $50 to $200 on labor costs. Parts and labor combined, installing the new part will cost you in the range of $150 to $600.
What does the vacuum modulator do on a Turbo 400?
It is equipped with a vacuum modulator that senses change in the engine’s vacuum due to throttle position and load changes . As these changes occur, the modulator adjusts the shift timing of the transmission according to the demand of the engine.
How do you test a vacuum modulator on a transmission?
- Block the rear wheels. ...
- Locate the vacuum modulator on the passenger side rear of the transmission. ...
- Pull the vacuum hose off the modulator and install the vacuum pump. ...
- Look for any transmission fluid running out of the vacuum port on the modulator, indicating a broken diaphragm.
How do you adjust transmission shift points?
- Shift up below the maximum RPM.
- Shift down above the idle RPM.
- The up and downshift points must be far enough apart that the new RPM after shifting up is not lower than the downshift point (and vice versa).
