Honda Accord 2008 Manual page 885

07/11/02 08:46:44 61TA0000_140_0042
Automatic Transmission
System Description (cont'd)
Electronic Control System (cont'd)
Grade Logic Control: Ascending Control
When the PCM determines that the vehicle is climbing a hill in D and D3, the system extends the engagement area of
2nd, 3rd, and 4th gears to prevent the transmission from frequently shifting between 2nd and 3rd gears, between 3rd
and 4th gears, and between 4th and 5th gears. The PCM does this so the vehicle can run smooth and have more power
when needed.
Shift programs stored in the PCM between 2nd and 3rd gears, between 3rd and 4th gears, and between 4th and 5th
gears, enable it to automatically select the most suitable gear according to the magnitude of a gradient.
＊０３
Grade Logic Control: Descending Control
When the PCM determines that the vehicle is going down a hill in D and D3, the upshift speed from 4th to 5th gear,
from 3rd to 4th gear, and from 2nd to 3rd gear (when the throttle is closed) becomes faster than the set speed for flat
road driving to extend the 4th gear, 3rd gear, and 2nd gear driving area. This, in combination with engine braking from
the deceleration lock-up, achieves smooth driving when the vehicle is descending. There are three descending modes
with different 4th gear driving areas, 3rd gear driving areas, and 2nd gear driving areas according to the magnitude of
a gradient stored in the PCM. When the vehicle is in 5th gear or 4th gear, and you are decelerating when you are
applying the brakes on a steep hill, the transmission will downshift to lower gear. When you accelerate, the
transmission will then return to a higher gear.
＊０４
14-40
ASCENDING MODE: Upshift Schedule
100 %
1ST 2ND 2ND
50
0
Vehicle speed
DESCENDING MODE: Downshift Schedule
100 %
1ST 3RD
2ND 2ND
50
0
Vehicle speed
3RD 3RD 4TH
4TH 5TH
3RD 4TH 4TH 5TH
: FLAT ROAD MODE
: GRADUAL ASCENDING MODE
: MEDIUM ASCENDING MODE
: STEEP ASCENDING MODE
: HEAVY STEEP ASCENDING MODE
: FLAT ROAD MODE
: GRADUAL DESCENDING MODE
: MEDIUM DESCENDING MODE
: STEEP DESCENDING MODE