Acura RL. Manual - part 229

Fig. 54: Hydraulic Pressure Flow Diagram (D Position: Driving In 5th Gear)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

M Position: Driving in 1st gear (engaged with 1st and 1st-hold clutches)

Line pressure (1) regulated by the regulator valve flows to shift solenoid valves. The PCM switches the shift
solenoid valves ON and OFF. The conditions of the shift solenoid valves and positions of the shift valves are as
follows:



Shift solenoid valve A is OFF, and closes the port of shift solenoid valve A pressure (SA); shift valve A
remains on the left side.



Shift solenoid valve B is turned ON, and closes the port of shift solenoid valve B pressure (SB); shift
valve B and shift valve E remain on the left side.



Shift solenoid valve C is turned ON, and closes the port of shift solenoid valve C pressure (SC); shift
valve C and shift valve D remain on the left side.



Shift solenoid valve D is OFF, and closes the port of shift solenoid valve D pressure (SD).

Line pressure (4) becomes 1st clutch pressure (10) at shift valve D, and flows to the 1st clutch. The 1st clutch is
engaged. The PCM actuates A/T clutch pressure control solenoid valve C, and A/T clutch pressure control
solenoid valve C pressure (58) is applied to CPC valve C via the lock-up shift valve. CPC valve C regulates line
pressure (4), and line pressure (4) becomes CPC C pressure (4C). CPC C pressure (4C) flows to shift valve B
via shift valves D, E, and C, and becomes 1st-hold clutch pressure (15) at shift valve B. 1st-hold clutch pressure

2007 Acura RL

2005-08 TRANSMISSION Automatic Transmission - RL

Friday, June 05, 2009 1:18:11 PM

Page 87

(15) is applied to the 1st-hold clutch, and the 1st-hold clutch is engaged.

Fig. 55: Hydraulic Pressure Flow Diagram (M Position: Driving In 1st Gear)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

R Position: Shifting to the R position from the P or N position

The PCM switches the shift solenoid valves ON and OFF. The conditions of the shift solenoid valves and
positions of the shift valves are as follows:



Shift solenoid valve A is OFF, and closes the port of shift solenoid valve A pressure (SA); shift valve A
remains on the left side.



Shift solenoid valve B is turned ON, and closes the port of shift solenoid valve B pressure (SB); shift
valve B and shift valve E remain on the left side.



Shift solenoid valve C is OFF, and opens the port of shift solenoid valve C pressure (SC); shift valve C
and shift valve D move to the right side.



Shift solenoid valve D is turned ON, and opens the port of shift solenoid valve D pressure (SD); reverse
control valve moves to the right side.

NOTE:

When used, "left" or "right" indicates direction on the hydraulic circuit.

2007 Acura RL

2005-08 TRANSMISSION Automatic Transmission - RL

Friday, June 05, 2009 1:18:11 PM

Page 88

The manual valve is moved to the R position, and line pressure (1) becomes line pressure (3) at the manual
valve. Line pressure (3) passes through the reverse control valve, and becomes line pressure (3A), then flows to
the servo valve. Line pressure (3A) pushes the servo valve to the reverse position. Line pressure (3) also flows
to the reverse CPC valve, and becomes reverse CPC pressure (3B) (3"). Reverse CPC pressure (3") becomes 5th
clutch pressure (50) at the manual valve, and 5th clutch pressure (50) flows to the 5th clutch. The 5th clutch is
engaged by the reverse CPC pressure.

Fig. 56: Hydraulic Pressure Flow Diagram (R Position: Shifting To R Position From P Position)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

R Position: Driving in reverse gear

As the speed of the vehicle reaches the programmed value, the PCM turns shift solenoid valve A ON, and shift
solenoid valve A uncovers the port of shift solenoid valve A pressure (SA) to shift valve A. Shift valve A is
moved to the right side to switch the port of line pressure (3') and reverse CPC pressure (3B) leading to the 5th
clutch. Line pressure (3) flows to the manual valve via the servo valve and shift valve A, and becomes 5th
clutch pressure (50) at the manual valve. The 5th clutch pressure (50) flows to the 5th clutch, and the 5th clutch
is engaged by the line pressure.

Reverse Inhibitor Control

NOTE:

When used, "left" or "right" indicates direction on the hydraulic circuit.

2007 Acura RL

2005-08 TRANSMISSION Automatic Transmission - RL

Friday, June 05, 2009 1:18:11 PM

Page 89

When R is selected while the vehicle is moving forward, the PCM keeps shift solenoid valve D OFF so that
shift solenoid valve D pressure (SD) is not applied to the reverse control valve. Line pressure (3) stops at the
reverse control valve, and is not applied to the servo valve. No power is transmitted to the reverse direction.

Fig. 57: Hydraulic Pressure Flow Diagram (R Position: Driving In Reverse Gear)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

P Position

The PCM switches the shift solenoid valves ON and OFF. The conditions of the shift solenoid valves and
positions of the shift valves are as follows:



Shift solenoid valve A is OFF, and closes the port of shift solenoid valve A pressure (SA); shift valve A
remains on the left side.



Shift solenoid valve B is turned ON, and closes the port of shift solenoid valve B pressure (SB); shift
valve B and shift valve E remain on the left side.



Shift solenoid valve C is OFF, and opens the port of shift solenoid valve C pressure (SC); shift valve C
and shift valve D move to the right side.



Shift solenoid valve D is turned ON, and opens the port of shift solenoid valve D pressure (SD); reverse

NOTE:

When used, "left" or "right" indicates direction on the hydraulic circuit.

2007 Acura RL

2005-08 TRANSMISSION Automatic Transmission - RL

Friday, June 05, 2009 1:18:11 PM

Page 90

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