Honda Civic Service Manual page 885

Description
Electronic Control System ('99 - 00 Modelsl (cont'dl
Grade Logic Control System
How it works:
The PcM compares actual driving conditions with memorized driving conditions. based on the input from the vehicle
speed sensor, the throttle position sensor, the manifold absolute pressure sensor, the engine coolant temperature sensor,
the brake switch signal, and the shift lever position signal, to control shifting while the vehicle is ascending or descending
a slope.
Ascending Control
When the PCM determines that the vehicle is climbing a hill in E position, the system selects the most suitable shift
schedule (pulley ratio) according to the magnitude of a gradient. so the vehicle can run smooth and have more power
when needed. There are three ascending modes with different shift schedules according to the magnitude ot a gradient in
the PCM.
Descending Control
when the PCM determines that the vehicle is going down a hill in E position. the system selects the most suitable shift
schedule (pulley ratio) according to the magnitude of a gradient. This, in combinstion with engine braking, achieves
smooth driving when the vehicle is descending, There are three descending modes with different shift schedules accord-
ing to the magnitude of a gradient in the PCM.
14-206