• Normally, line pressure (12) is retained because the 3-2 timing solenoid valve is turned OFF.
• The line pressure overcomes spring force to push the valve to the left side.
• When shifting from 1GR to 2GR, 2-4 brake application pressure (9) passes through the 3-2 timing valve to engage the 2-4 brake band with the solenoid valve ON. Brake band application pressure (9) from the other circuit also engages the 2-4 brake band.
• When shifting from 3GR to 2GR, the 3-2 timing valve drains 2-4 brake release pressure (15) to achieve shifting timing. When 2-4 brake band application side pressure reaches the specified pressure, the 3-2 timing solenoid valve goes OFF, and the 3-2 timing valve moves to the left to close outlet port (9).
• As a result, the 2-4 brake application side pressure increases gradually, improving 1GR to 2GR upshift response and reducing shift shock.
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1
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From 2-4 brake band
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2
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To 2-4 brake band
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3
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From 1-2 shift valve
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4
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From pressure regulator valve
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5
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3-2 timing solenoid valve: ON
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6
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To 3-4 clutch
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7
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3-2 timing solenoid valve: OFF
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