Chapter 42, Problem 1RQ

Although computers receive different information from a variety of sensors, the decisions for shifting are actually based on more than the inputs. What are they based on?

To determine

The decisions shift or not to shift in the automatic transmission.

Answer to Problem 1RQ

The decisions to shift or not to shift in automatic transmission are based on the shift schedule and logic.

Explanation of Solution

Transmission control module (TCM) is designed or programmed in such a way that it receives signals from sensors, engine related or driver-controlled sensors to control the shift timing, torque converter clutch and shift feel. But the decisions to shift or not to shift is based on the shift schedule and logic. In shift schedule composed of shift points and are precisely selected based on the signals from appropriate sensors. Shift schedule logic select the appropriate gear. Other inputs TCM used to control shift speed are:

Throttle position.

Manifold absolute pressure.

Mass airflow.

Intake air temperature.

Barometric pressure.

Engine coolant temperature.

Crank shaft position.