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Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 132 (Automatic Transmission - 4L60-E/4L65-E/4L70-E - Introduction (2 Of 2)) >> Description and Operation >> Automatic Transmission Hydraulic Diagrams >> Overdrive Range, 3-2 Downshift >> Notes

Overdrive Range, 3-2 Downshift: Notes

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Similar to a forced 4-3 downshift, a forced 3-2 downshift can occur because of minimum throttle (coastdown conditions), heavy throttle or increased engine load. In order to achieve a forced 3-2 downshift, the PCM energizes the 2-3 shift solenoid valve and the following changes occur:

Energized by the PCM, the normally open solenoid closes and blocks the signal B fluid from exhausting through the solenoid. This creates pressure in the signal B fluid circuit at the solenoid end of the 2-3 shift valve.