When the gear selector lever is in the Park (P) position, fluid is drawn into the pump through the transmission fluid filter assembly. Line pressure is then directed to the following valves:
Manual Valve
Mechanically controlled by the gear selector lever, the manual valve is in the Park (P) position and prevents line pressure from the pressure regulator valve from entering the reverse and drive fluid circuits.
Actuator Feed Limit Valve
Line pressure is regulated through the valve into the actuator feed limit circuit. Actuator feed limit fluid passes through orifice #10 to a differential area to move the valve against actuator feed limit valve spring pressure. Actuator feed limit fluid is routed to the pressure control solenoids, the shift solenoid, and to the #4 ball check valve.
TCC Regulated Apply Valve
Shift solenoid fluid is routed to the TCC regulated apply valve and moves the valve against TCC regulated apply valve spring force.
Default Override Valve
Shift solenoid fluid is routed to the default override valve and moves the valve against default override valve spring force.
R1/456 Pressure Control (PC) Solenoid
The R1/456 PC solenoid is energized (ON) allowing actuator feed limit fluid to enter the PCS R1/456 clutch fluid circuit. PCS R1/456 clutch fluid is then routed through orifice #11 to the R1/4-5-6 clutch regulator valve, and through orifice #34 to the R1/4-5-6 clutch boost valve.
R1/4-5-6 Clutch Regulator Valve
PCS R1/456 clutch fluid at the R1/4-5-6 clutch regulator valve, opposes R1/4-5-6 clutch regulator spring force and orificed R1/456 clutch feedback fluid pressure to regulate line pressure into the R1/456 clutch feed circuit. R1/456 clutch feed fluid is routed to the R1/4-5-6 clutch boost valve and to the clutch select valve.
R1/4-5-6 Clutch Boost Valve
PCS R1/456 clutch fluid pressure acts on a differential area, moving the R1/4-5-6 clutch boost valve against R1/4-5-6 clutch boost valve spring force, to regulate R1/456 clutch feed fluid into the R1/456 clutch feedback circuit. As PCS R1/456 clutch fluid pressure is increased to a given value, the R1/4-5-6 clutch boost valve opens the R1/456 clutch feedback circuit to exhaust backfill. This results in the R1/4-5-6 clutch regulator valve moving to the full feed position, sending full R1/456 clutch feed pressure (full line pressure) to the low and reverse clutch.
Shift Solenoid
The shift solenoid is energized (ON) allowing actuator feed limit fluid to enter the shift solenoid circuit. Shift solenoid fluid is routed to the clutch select valve through orifice #13, to the TCC regulated apply valve through orifice #14, and through orifice #44 to the default override valve.
Clutch Select Valve
Shift solenoid fluid is routed to the clutch select valve and moves the valve against clutch select valve spring force. This allows R1/456 clutch feed fluid to pass through the valve and enter the R1 circuit. R1 fluid is then routed through orifice #42 to the low and reverse clutch assembly in preparation for a shift into low or reverse gear.
Low and Reverse Clutch
R1/456 fluid enters the transmission case assembly and moves the low and reverse clutch piston against spring force to apply the low and reverse clutch plates. In Park range, the low and reverse clutch has no effect. However, when Reverse or a forward range is selected, only one apply device has to be energized, which helps create a smooth starting motion.
Accumulator
PCS R1/456 clutch fluid is also routed to an accumulator valve. The accumulator valve is used to dampen any pressure irregularities occurring in the PCS R1/456 clutch fluid circuit. This helps to control clutch apply fluid pressure and clutch apply feel.
Roof
Sunroof
On vehicles with this feature, the sunroof only operates when the ignition is
turned to ON/RUN or Retained Accessory Power (RAP) is active.
Open/Close: To open the sunroof, press and hold the rear of the switch. To close
the sunroof, press and hold the front of the switch.
Vent: Pre ...
Door Lock and Ignition Lock Folding and Non-Folding Key Cutting
High Security keys are available from the service parts system.
Obtain the key code from the security card or from the GM Dealer World, Parts,
Key Code Look Up system.
If you have the key code and access to a Triax-E., BD Laser or other code key
cutting machine from the GM Dealer Equipment C ...
Instrument Panel Upper Trim Panel Replacement - Left Side
Instrument Panel Upper Trim Panel Replacement - Left Side
Callout
Component Name
Preliminary Procedure
Remove the instrument cluster assembly. Refer to Instrument Cluster
Replacement.
Remove the instrument panel center mo ...