GM Service Manual Online
For 1990-2009 cars only

When the gear selector is moved to the Neutral (N) position, the hydraulic and electrical system operation is identical to Park (P) range. However, if Neutral is selected after the vehicle was operating in Reverse (R), the following changes would occur in the hydraulic system:

Hybrid Low, 1-2 Clutch Releases

Pressure Control (PC) Solenoid 3 Trim

The PC solenoid 3 trim is de-energized (OFF) allowing PCS 3 signal fluid to exhaust from the hybrid low, 1-2 clutch regulator valve; the hybrid low, 1-2 clutch boost valve; and the shift solenoid valve - mode B.

Hybrid Low, 1-2 Clutch Assembly

HL 12 clutch fluid exhausts from the hybrid low, 1-2 clutch to the shift solenoid valve - mode B allowing the hybrid low, 1-2 clutch to release.

Shift Solenoid Valve - Mode B

HL 12 clutch fluid passes through the shift solenoid valve - mode B and into the HL 12 clutch/4th clutch feed fluid circuit and is routed to the hybrid low, 1-2 clutch regulator valve.

Hybrid Low, 1-2 Clutch Boost Valve

Hybrid low, 1-2 clutch boost valve spring force moves the hybrid low, 1-2 clutch boost valve to the released position, allowing HL 12 clutch/4th clutch feedback fluid pressure to exhaust into the HL 12 clutch/4th clutch feed circuit.

Hybrid Low, 1-2 Clutch Regulator Valve

Hybrid low, 1-2 clutch regulator valve spring force moves the hybrid low, 1-2 clutch regulator valve to the released position, allowing HL 12 clutch/4th clutch feed fluid pressure to exhaust through the valve into the backfill circuit.

Clutch Piston Exhaust Blowoff Ball Valve

Excess fluid pressure in the backfill circuit exhausts at the clutch piston exhaust blowoff ball valve in order to maintain a constant backfill fluid pressure of 2 psi.

Neutral - Engine Running


Object Number: 1968876  Size: FS