Driving in 2nd gear

WARNING: This page is about a different car, the 2013 Acura MDX, 2012 Acura MDX, 2011 Acura MDX, and 2010 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.

The condition of shift solenoid valves A and B in 2nd gear remains the same as in 1st gear, which turns shift solenoid valves A and B ON. As the speed of the vehicle reaches the programmed value, the PCM activates A/T clutch pressure control solenoid valve A, and applies CPC pressure (55) to shift valve A. Shift valve A remains on the right side as with 1st gear. The CPC pressure (55) from A/T clutch pressure control solenoid valve A becomes 2nd clutch pressure (20) at shift valve A, and flows to the 2nd clutch. Then the 2nd clutch is engaged by 2nd clutch pressure (20). The 1st clutch is also engaged, but since the rotation speed of the countershaft exceeds that of 1st gear, no power is transmitted because the one-way clutch causes 1st gear to free-wheel.

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

Fig 1: Automatic Transmission Hydraulic Flow Diagram - Driving In 2nd Gear

Courtesy of AMERICAN HONDA MOTOR CO., INC.