Acura RL. Manual - part 228

Fig. 50: Hydraulic Pressure Flow Diagram (D Position: Driving In 3rd Gear) 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

D Position: Shifting between 3rd gear and 4th gear 

As the speed of the vehicle reaches the programmed value, the PCM turns shift solenoid valve C OFF, and shift 
solenoid valve C uncovers the port of shift solenoid valve C pressure (SC) to shift valve C. Shift solenoid valve 
A remains ON, and shift solenoid valve B remains OFF. Shift valve C is moved to the right side to switch the 
port of line pressure (4) and CPC B pressure (4B) leading to the 3rd clutch. Shift valve C also uncovers the port 
of CPC A pressure (4A) leading to the 4th clutch. The PCM actuates A/T clutch pressure control solenoid 
valves A and B. A/T clutch pressure control solenoid valve A pressure (56) is applied to CPC valve A, and A/T 
clutch pressure control solenoid valve B pressure (57) is applied to CPC valve B. CPC valve A regulates line 
pressure (4), and line pressure (4) becomes CPC A pressure (4A). CPC A pressure (4A) flows to shift valve B 
via shift valves C and A, and becomes 4th clutch pressure (40) at shift valve B. The 3rd clutch pressure (30) is 
changed to CPC pressure, and the 4th clutch is engaged by the CPC pressure. The 1st clutch is also engaged, but 
no power is transmitted because of the one-way clutch. 

NOTE:

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

 

2007 Acura RL 

2005-08 TRANSMISSION Automatic Transmission - RL

  

me 

 

Friday, June 05, 2009 1:18:11 PM

Page 83 

© 2005 Mitchell Repair Information Company, LLC. 

Fig. 51: Hydraulic Pressure Flow Diagram (D Position: Shifting Between 3rd Gear And 4th Gear) 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

D Position: Driving in 4th gear 

The PCM turns shift solenoid valve A OFF, and shift solenoid valve A covers the port of shift solenoid valve A 
pressure (SA) to shift valve A. Shift solenoid valves B and C remain OFF. Shift valve A is moved to the left 
side to switch the port of line pressure (5B), CPC A pressure (5A) (5L) leading to the 4th clutch, and 3rd clutch 
pressure (30) releasing 3rd clutch pressure. CPC A pressure (5L) changes to line pressure (5L) and 4th clutch 
pressure (40) is changed to line pressure, and the 4th clutch is engaged by the line pressure. The 1st clutch is 
also engaged, but no power is transmitted because of the one-way clutch. 

NOTE:

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

 

2007 Acura RL 

2005-08 TRANSMISSION Automatic Transmission - RL

  

me 

 

Friday, June 05, 2009 1:18:11 PM

Page 84 

© 2005 Mitchell Repair Information Company, LLC. 

Fig. 52: Hydraulic Pressure Flow Diagram (D Position: Driving In 4th Gear) 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

D Position: Shifting between 4th gear and 5th gear 

As the speed of the vehicle reaches the programmed value, the PCM turns shift solenoid valve CON, and shift 
solenoid valve C covers the port of shift solenoid valve C pressure (SC) to shift valve C. Shift solenoid valve A 
remains OFF, and shift solenoid valve B remains OFF. Shift valve C is moved to the left side to switch the port 
of line pressure (4) and CPC A pressure (4A) leading to the 4th clutch. Shift valve C also uncovers the port of 
CPC B pressure (4B) leading to the 5th clutch. The PCM actuates A/T clutch pressure control solenoid valves A 
and B. A/T clutch pressure control solenoid valve A pressure (56) is applied to CPC valve A, and A/T clutch 
pressure control solenoid valve B pressure (57) is applied to CPC valve B. CPC valve B regulates line pressure 
(4"), and line pressure (4") becomes CPC B pressure (4B). CPC B pressure (4B) flows to shift valve A via shift 
valves C and B, and becomes 5th clutch pressure (51) at shift valve A. The 4th clutch pressure (40) is changed 
to CPC pressure, and the 5th clutch is engaged by the CPC pressure. The 1st clutch is also engaged, but no 
power is transmitted because of the one-way clutch. 

NOTE:

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

 

2007 Acura RL 

2005-08 TRANSMISSION Automatic Transmission - RL

  

me 

 

Friday, June 05, 2009 1:18:11 PM

Page 85 

© 2005 Mitchell Repair Information Company, LLC. 

Fig. 53: Hydraulic Pressure Flow Diagram (D Position: Shifting Between 4th Gear And 5th Gear) 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

D Position: Driving in 5th gear 

The PCM turns shift solenoid valve B ON, and shift solenoid valve B covers the port of shift solenoid valve B 
pressure (SB) to shift valve B. Shift solenoid valve A remains OFF, and shift solenoid valve C remains ON. 
Shift valve B is moved to the left side to switch the port of line pressure (5H), CPC B pressure (5D) leading to 
the 5th clutch, and 4th clutch pressure (40) releasing 4th clutch pressure. CPC B pressure (5H) changes to line 
pressure (5H) and 5th clutch pressure (51) (50) is changed to line pressure, and the 5th clutch is engaged by the 
line pressure. The 1st clutch is also engaged, but no power is transmitted because of the one-way clutch. 

NOTE:

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

 

2007 Acura RL 

2005-08 TRANSMISSION Automatic Transmission - RL

  

me 

 

Friday, June 05, 2009 1:18:11 PM

Page 86 

© 2005 Mitchell Repair Information Company, LLC.