Honda 2004 Odyssey Service Manual page 645

Automatic Transmission
System Description (cont'd)
Electronic Control System (cont'd)
Grade Logic Control System
How it works:
The PCM compares actual driving conditions with memorized driving conditions, based on the input from the
countershaft speed sensor, the throttle position sensor, the engine coolant temperature sensor, the brake pedal
position switch signal, and the shift lever position signal, to control shifting while the vehicle is ascending or
descending a slope, or reducing speed.
SENSORS/SWITCHES
Countershaft Speed
Sensor
Throttle Position
Sensor
Engine Coolant
Temperature Sensor
Transmission Range
Switch
14-32
SIGNALS DETECTED
Driving resistance
Coolant temperature
D4 or D3 Position
PCM
Judgment of controlling area
Detection of
Calculation
standard
of actual
acceleration
acceleration
(in Memory)
Calculation of gradient
Selection of shifting mode
• Normal mode (Flat road mode)
• Ascending mode
• Gradual ascending mode
• Medium ascending mode
• Steep ascending mode
• Descending mode
• Gradual descending mode
• Steep descending mode
• Deceleration mode
Automatic 4-speed transmission
Calculation
of decelera-
tion