Pontiac Fiero 1988 Service Manual page 756

HYDRAULIC DIAGNOSIS 125C-15
PARK—ENGINE RUNNING
DIRECT CLUTCH - RELEASED FORWARD CLUTCH - RELEASED LO A I D IEWEISE CLUTCH - RELEASED
CONWERTER CLUTCH - RELEASED INTERMEDIATE BAND - RELEASED ROLLER CLUTCH - NOT HOLDING
With the selector lever in the Park (P) position, oil from the pump is directed to the following:
1. Pressure Regulator Valve
2. Converter and Lubrication System
3. Pump Slide
4. Manual Valve
5. Pressure Relief Valve
6. Line Pressure Tap
Oil flows from the pump to the pressure regulator valve which regulates the pump pressure. When
the pump output exceeds the demand of line pressure, oil from the pressure regulator valve is directed
to the converter feed passage to fill the converter. Converter return oil is directed t o the transmission
cooler. Oil from the cooler is directed to the transmission lubrication system.
Oil is also directed from the pressure regulator valve t o the pump slide t o decrease pump output to
the pressure of the regulator valve spring force, or 4 8 2 kPa (70 psi). Line pressure acts on the pressure
relief valve which will exhaust any oil above 2,068 to 3,102 kPa ( 3 0 0 - 4 5 0 psi).
Line pressure at the manual valve is available for use in other drive ranges.
SUMMARY
The converter is filled; all clutches and the band are released. Manual linkage has t h e parking pawl
engaged in the reaction internal gear lugs. The transmission is in Park (P). Line pressure is regulated
to approximately 4 8 3 kPa (70 psi).
J H 0 0 1 8 1 2 5 C
Figure 12 Park-Engine Running