Automatic transmission systems have modulators that essentially control pressure according to the current load of the vehicle. The load here means the pressure and weight excepted on the vehicle’s engine. It allows the transmission to shift accordingly. Modulators work hand in hand with governors to determine ideal shifting point. Vacuum modulators are connected to the intake valve via a vacuum line. This line calculates the amount of vacuum in the engine.
If you need 5-Star Phoenix transmission repair, call us now for a FREE check-up:
These modulators require modulator valves to function optimally. A modulator valve controls shifting. A modulator valve contains the following components:
- Throttle valve
Unlike manual transmission where the driver is responsible for shifting gears, the modulator valve that changes the gears in automatic transmission. It shifts the transmission according to the intake manifold vacuum. When you put force on the gas pedal throttle plate opens reducing the vacuum the modulator valve makes the transmission to downshift. If you release the gas pedal vacuum increases causing a transmission upshift.
For instance, when the car is heading downhill the load on the engine is much smaller compared to driving uphill with lots of passengers.
If your car’s modulator valve fails, your transmission shift will perform poorly. If the worn out valves are left unattended, the transmission will start to burn the fluid because the engine vacuum operates the modulator valve.
A leaking valve allows the engine to suck transmission fluid into the intake manifold through a vacuum line. The engine then burns the transmission fluid. As a result, the transmission will lack enough transmission fluid.
A bad modulator will manifest the following symptoms:
Poor engine performance
If your modulator has a problem you will notice a reduction in engine performance. In addition, you will experience acceleration problems. Ultimately, your vehicle efficiency and fuel economy will be affected.
A warning light illuminating from the dashboard is yet another noticeable sign of a bad modulator. The computer detects when the modulator is faulty and triggers the engine warning light. However, when you see engine warning light, do not automatically assume that the modulator is bad. There are numerous reasons why an engine warning comes on. Check for other signs.
A modulator allows the transmission to shift correctly. If the modulator is faulty, you will experience problems when shifting, i.e., untimely and hard shifting.
A bad modulator will be unable to regulate emission properly. As a result, you will notice an excessive amount of emission coming out of the exhaust.
Learn more about your vehicle’s transmission: