Chevrolet Equinox Service Manual: Reverse Automatic Transmission Unit

When the gear selector lever is moved to the Reverse (R) position (from the Park position)the normally high 35R pressure control solenoid 2 is commanded ON and the followingchanges occur in the transmission’s hydraulic and electrical systems:

Fluid Pressure Directed in Preparation for a Shift

Manual Valve

With the manual valve in the reverse position, line pressure is directed into thereverse fluid circuit to the #2- ball check valve and clutch select valve-3.

#2 Ball Check Valve

Reverse fluid seats the #2-ball check valve against the solenoid-1 fluid passage andfluid is forced through orifice-#15 into the CSV2 enable circuit.

Clutch Select Valve 2

CSV2 enable fluid, present at the valve from Park position, continues to hold theclutch select valve-2 against clutch select valve-2 spring force.

Low & Reverse Clutch Applies

Clutch Select Valve 3

Reverse fluid from the manual valve is routed to clutch select valve-3 to combinewith clutch select valve-3 spring force to keep the valve in the off position. Thisallows reverse fluid to pass through the valve and enter the 3-5-clutch reverse feedcircuit. The 3-5-clutch reverse feed fluid from the clutch select valve-3 is alsorouted to #5-ball check valve.

Low & Reverse Clutch

R1 supply fluid passes through orifice #18 and unseats check ball #8. R1 supply fluidenters the low & reverse clutch piston circuit and moves the piston against the springforce to apply the low & reverse clutch plates.

#5 Ball Check Valve

The 3-5-clutch reverse feed fluid seats #5-ball check valve against the drive 1-6-circuit allowing 3-5-clutch reverse feed fluid to enter the 3-5-reverse supply circuit.The 3-5-reverse supply fluid is then routed to #7 ball check valve and through orifice-#16where is enters the 3-5-reverse feed circuit. The 3-5- reverse feed passes throughorifice-#34 and then isrouted to the 3-5-reverse clutch regulator valve.

3-5 Reverse Clutch Applies

35R Pressure Control Solenoid 2

The 35R pressure control solenoid-2 is energized (HIGH) allowing actuator feed limitfluid to enter the PCS 3-5-reverse clutch circuit. PCS 3-5- reverse clutch fluid isthen routed through orifice- #36 to the 3-5-reverse clutch regulator valve and throughorifice-#37 to the 3-5- reverse boost valve.

3-5 Reverse Clutch Regulator Valve

PCS 3-5-reverse clutch fluid moves the 3-5-reverse clutch regulator valve against3-5- reverse clutch regulator valve spring force and 3-5-reverse clutch feedback fluid.This allows 3-5-reverse feed to pass through the valve and enter the 3-5-reverse clutchcircuit. The 3-5-reverse clutch fluid is then routed to the 3-5-reverse clutch andthe 3-5-reverse boost valve. PS2 fluidfrom pressure switch-2 exhausts through the valve allowing the switch to close.

3-5 Reverse Boost Valve

PCS 3-5-reverse clutch fluid pressure acts on a differential area moving the 3-5-reverseclutch boost valve against the 3-5-reverse clutch boost valve spring. The 3-5- reverseclutch fluid passes through the valve and enters the 3-5-reverse clutch feedback circuit.As PCS 3-5-reverse clutch fluid pressure is increased to a given value, the 3-5-reverseclutch boost valve opens the 3-5-reverseclutch feedback circuit to exhaust. This results in the 3-5-reverse clutch regulatorvalve moving to the full feed position sending full 3-5-clutch reverse feed pressure(full line pressure) to the clutch.

3-5 Reverse Clutch

The 3-5-reverse clutch fluid enters the 3-5R/456 clutch housing to move the pistonagainst spring force and compensator feed fluid to apply the 3-5-reverse clutch plates.

Reverse

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