In a torque converter with a modulated lock-up strategy, when does the lock-up clutch primarily engage?

In a torque converter with a modulated lock-up strategy, when does the lock-up clutch primarily engage?

• A. The lock-up clutch will apply as early as possible during the drive cycle.
• B. The lock-up clutch will apply based on throttle request.
• C. The lock-up clutch will only apply when the driver requests it.
• D. The lock-up clutch will apply only in high range.

Answer: (B)

In a modulated lock-up strategy, the system uses engine load as the main signal to decide when to engage the lock-up clutch. Throttle position directly reflects how much torque the engine is producing, so the control logic uses throttle request to determine when locking the converter will improve efficiency without compromising performance. When throttle is steady or light, the engine torque is suitable for lock-up, reducing slip and increasing fuel economy. During heavy acceleration or high torque demand, the clutch is allowed to slip to preserve torque multiplication, and it re-engages as throttle demand eases. So the lock-up clutch is primarily engaged in response to throttle input, not simply by driving actions or fixed ranges.

In a modulated lock-up strategy, the system uses engine load as the main signal to decide when to engage the lock-up clutch. Throttle position directly reflects how much torque the engine is producing, so the control logic uses throttle request to determine when locking the converter will improve efficiency without compromising performance. When throttle is steady or light, the engine torque is suitable for lock-up, reducing slip and increasing fuel economy. During heavy acceleration or high torque demand, the clutch is allowed to slip to preserve torque multiplication, and it re-engages as throttle demand eases. So the lock-up clutch is primarily engaged in response to throttle input, not simply by driving actions or fixed ranges.