1-2 & 2-3 Shift Solenoid Valves

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NOTE: The manual valve hydraulically can override the shift solenoids. Only in "D4" do the shift solenoid states totally determine what gear the transmission is in. In the other manual valve positions, the transmission shifts hydraulically and the shift solenoid states catch up when the throttle position and the vehicle speed fall into the correct ranges.

The 1-2 and 2-3 shift solenoid valves (also called "A" and "B" solenoids) are identical devices that control the movement of the 1-2 and 2-3 shift valves (the 3-4 shift valve is not directly controlled by a shift solenoid). The solenoids are normally open exhaust valves that work in four combinations to shift the transmission into different gears. See SHIFT SOLENOID OPERATION table.

The PCM energizes each solenoid by grounding the solenoid through an internal quad driver. This sends current through the coil winding in the solenoid and moves the internal plunger out of the exhaust position. When ON, the solenoid redirects fluid to move a shift valve.

The PCM-controlled shift solenoids eliminate the need for T.V. and governor pressures to control shift valve operation.

SHIFT SOLENOID OPERATION

Gearshift Lever Position

1-2 Solenoid

2-3 Solenoid

"OD" (Overdrive)

First Gear

Second Gear

Off

Third Gear

Off

Overdrive

Off

"D" (Drive)

First Gear

Second Gear

Off

Third Gear

Off

"2" (Intermediate)

First Gear

Second Gear ⁽¹⁾

Off

"1" (Low)

First Gear

Second Gear

Off

"R" (Reverse)

"N" (Neutral)

"P" (Park)

⁽¹⁾	Gear is only available at vehicle speeds greater than 30-35 MPH.