Which pressure provides the load signal to the control valve body?

Which pressure provides the load signal to the control valve body?

• A. Governor pressure
• B. Main pressure
• C. Modulator pressure
• D. MPRV pressure

Answer: (C)

The pressure that acts as the load signal to the control valve body is the modulator pressure. This pressure is tied to engine load (throttle position) and often comes from the intake manifold or a dedicated modulator source, so it rises as the engine works harder and falls when the load decreases. The valve body uses this signal to adjust shift timing and clutch engagements to match how hard the engine is working, helping prevent lugging and optimize performance. In contrast, governor pressure reflects vehicle speed, not how hard the engine is pulling; main pressure is simply the pump’s hydraulic supply to the system; and MPRV pressure is related to protection/relief functions rather than providing the load signal.

The pressure that acts as the load signal to the control valve body is the modulator pressure. This pressure is tied to engine load (throttle position) and often comes from the intake manifold or a dedicated modulator source, so it rises as the engine works harder and falls when the load decreases. The valve body uses this signal to adjust shift timing and clutch engagements to match how hard the engine is working, helping prevent lugging and optimize performance.

In contrast, governor pressure reflects vehicle speed, not how hard the engine is pulling; main pressure is simply the pump’s hydraulic supply to the system; and MPRV pressure is related to protection/relief functions rather than providing the load signal.