Acura RSX Honda Integra. Manual — part 229

０２

Shift Control

14-41

Transmission
Range
Switch Signal

PCM

Brake Pedal Position
Switch Signal

Engine RPM
control

Engine RPM Signal

Transmission Gear
Selection Switch Signal

Throttle Position
Sensor Signal

Output Shaft (Countershaft)
Speed Sensor Signal

Input Shaft (Mainshaft)
Speed Sensor Signal

ATF Temperature
Sensor Signal

Engine Coolant
Temperature
Sensor Signal

Shift position
control

Fail-safe control

Actual Driving
Shift Position

Read of ATF
Temperature

Master Target of
Shifting Position

Grade Logic Control

Calculation of
gradient

Barometric
Pressure
Sensor Signal

• Ascending mode

Descending mode

•

Multiplex

Co

mp

ariso

n

w

ith

Sig

n

als

A/T Gear
Position
Indicator

Gauge Assembly

Shift
Indicator

Correction of Data
Selection of
shifting mode

Correction of engine
coolant temperature
sensor signal data

Shift Solenoid
Valve A

Shift Solenoid
Valve B

Shift Solenoid
Valve C

Shift Solenoid
Valve D

Shift Solenoid
Valve E

Tran

smi

ssi

on

R

ange

sw

it

ch

The PCM instantly determines which gear should be selected by various signals sent from sensors and switches, and
it actuates the shift solenoid valves A, B, C, D, and E to control shifting.

Also, a grade logic control system has been adopted to control shifting in D and D3 positions. The PCM compares
actual driving conditions with memorized driving conditions, based on the input from the throttle position sensor, the
engine coolant temperature sensor, the barometric pressure 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.

(cont’d)

05/06/27 17:48:43 61S6M040_140_0042

Electronic Control System (cont’d)

14-42

Automatic Transmission

System Description (cont’d)

The PCM turns the shift solenoid valves A, B, C, D, and E ON and OFF to control shifting transmission gear. The
combination of driving signals to shift solenoid valves A, B, C, D, and E are shown in table.

Position

Gear position

Shift solenoid valves

A

B

C

D

E

D, D3, M

Shifting from N position

OFF

ON

ON

OFF

OFF

Stays in 1st

ON

ON

ON

OFF

OFF

Shifting gears between 1st and 2nd

OFF

ON

ON

OFF

OFF

Stays in 2nd

OFF

ON

OFF

ON

OFF or ON

Shifting gears between 2nd and 3rd

OFF

ON

ON

ON

OFF or ON

Stays in 3rd

OFF

OFF

ON

OFF

OFF or ON

D, M

Shifting gears between 3rd and 4th

OFF

OFF

OFF

OFF

OFF or ON

Stays in 4th

ON

OFF

OFF

OFF

OFF or ON

Shifting gears between 4th and 5th

ON

OFF

OFF

ON

OFF or ON

Stays in 5th

ON

OFF

ON

ON

OFF or ON

R

Shifting from P and N position

OFF

ON

OFF

OFF

ON

Stays in reverse

ON

ON

OFF

OFF

ON

Reverse inhibit

ON

ON

OFF

OFF

OFF

P

Park

OFF

ON

OFF

OFF

ON

N

Neutral

OFF

ON

ON

OFF

OFF

05/06/27 17:48:43 61S6M040_140_0043

＊０２

＊０３

Grade Logic Control: Ascending Control

Grade Logic Control: Descending Control

14-43

100 %

50

0

62 mph
(100 km/h)

Vehicle speed

ASCENDING MODE: Upshift Schedule

: FLAT ROAD MODE

: GRADUAL ASCENDING MODE

: MEDIUM ASCENDING MODE

: STEEP ASCENDING MODE

: HEAVY STEEP ASCENDING MODE

Thr

ot

tl

e

opening

50

0

DESCENDING MODE: Downshift Schedule

: FLAT ROAD MODE

: GRADUAL DESCENDING MODE

: MEDIUM DESCENDING MODE

: STEEP DESCENDING MODE

Vehicle speed

100 %

62 mph
(100 km/h)

Th

ro

tt

le

opening

3RD

4TH

4TH

2ND

1ST

5TH

2ND

3RD

3RD

4TH 4TH

2ND

1ST

5TH

2ND

3RD

When the PCM determines that the vehicle is climbing a hill in D and D3 positions, 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, so the vehicle can run smooth and have more
power when needed.
Shift schedules 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.

When the PCM determines that the vehicle is going down a hill in D and D3 positions, the shift-up 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 widen 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.

(cont’d)

05/06/27 17:48:43 61S6M040_140_0044

Electronic Control System (cont’d)

Deceleration Control

Shift Hold Control

14-44

Automatic Transmission

System Description (cont’d)

When the vehicle goes around a corner and needs to decelerate first and then accelerate, the PCM sets the data for
deceleration control to reduce the number of times the transmission shifts. When the vehicle is decelerating from
speeds above 27mph (43 km/h), the PCM shifts the transmission from 5th or 4th to 2nd earlier than normal to cope
with upcoming acceleration.

When the vehicle is driven aggressively on a winding road, the PCM will extend the engagement time of 3rd gear and
4th gear to prevent the transmission from frequently shifting between 3rd, 4th, and 5th gears. This allows the driver to
have more control for both acceleration and deceleration.
The PCM monitors the average change in vehicle speed and throttle over time. When these values exceed those for
normal driving conditions, the shift-up from 3rd to 4th gear and 4th to 5th gear is delayed. This gives more control
over power, and engine braking when the driver is driving aggressively around on a winding road. The transmission
will resume the normal shift-up pattern after the PCM determines that normal driving has resumed.

05/06/27 17:48:43 61S6M040_140_0045