GM Service Manual Online
For 1990-2009 cars only

Line Pressure Test


Object Number: 862975  Size: MF

Stepped Pressure Test

Important: Be sure to perform both Stepped Pressure Test and Maximum/Minimum Pressure Test of the Line Pressure Test.

  1. Run engine to bring transaxle to running temperature of 70°C (158°F).
  2. Turn engine OFF.
  3. Remove transaxle fluid temperature sensor and install pressure gage.
  4. Reinstall temperature sensor in wire harness.
  5. Connect the Scan tool.
  6. Key ON engine OFF. On first menu selection, select "Special Functions."
  7. Select Line Pressure.
  8. Transaxle in Park.
  9. Scan tool will prompt you to start engine.
  10. Select Run and the test will begin. The test will set engine speed to 1,500 RPM and command line pressure up in steps from 396-1518 kPa (57-220 psi) in 100 kPa (15 psi) intervals.
  11. As test is in progress, watch the gage to assure the gauge readings follow the commanded pressures. Use a dry erase marker to mark the face of the gage because it will be difficult to record the readings in time.

Command Line Pressure

Gage Readings Should Be In This Range

396 kPa (57 psi)

400-500 kPa (58-72 psi)

498 kPa (72 psi)

425-550 kPa (61-80 psi)

600 kPa (87 psi)

500-675 kPa (72-98 psi)

702 kPa (102 psi)

600-800 kPa (87-116 psi)

804 kPa (117 psi)

700-925 kPa (101-134 psi)

906 kPa (131 psi)

800-1050 kPa (116-152 psi)

1008 kPa (145 psi)

900-1175 kPa (130-170 psi)

1110 kPa (161 psi)

1000-1300 kPa (145-188 psi)

1212 kPa (175 psi)

1100-1400 kPa (159-203 psi)

1314 kPa (191 psi)

1200-1500 kPa (174-218 psi)

1416 kPa (205 psi)

1300-1650 kPa (188-240 psi)

1518 kPa (220 psi)

1500-1850 kPa (218-268 psi)

Maximum/Minimum Pressure Test

Oil pressure maximum and minimum values at idle should be checked using the following procedure:

       Important: For proper reverse operation, it is important to have at least 1206 kPa (175 psi) of system pressure in reverse at 70°C (158°F).

    • With gage connected and trans at operating temperature.
    • With engine idling in Park, line pressure should be 400-600 kPa (58-72 psi).
    • Remove line pressure fuse (10 amp TRS LP) UHJB.
    • With engine idling in P (Park), pressure should be 1206-1690 kPa (175-245 psi).

Important: High value may be slightly lower if transaxle temperature is greater than 110°C (230°F).

Important: With engine in Park, and the 10 amp TRS LP line pressure fuse removed, minimum pressure should be 1206 kPa (175 psi).

Remove pressure gage, install temperature sensor, use Saturn P/N 21485278 sealant with Teflon® on threads (or equivalent). After the sensor has been connected, clear diagnostic trouble codes caused by having the sensor disconnected.

Tighten
Tighten the transaxle fluid temperature sensor-to-case to 8 N·m (71 lb in).

Clutch Damage Check Procedure

  1. Place the vehicle in Park.
  2. Remove end cover, refer to End Cover Replacement .
  3. Rotate the input shaft by hand, turning the 1st clutch housing in both directions.
  4. • If input shaft turns freely in only one direction, the 1st clutch is binding. Repair 1st clutch. Refer to 1st Clutch, 1st Drive Gear and 1st Driven Gear Replacement - On Vehicle .
    • If input shaft will not turn freely in either direction, 2nd, 3rd or 4th clutch is binding. Repair clutches. Refer to 1st Clutch, 1st Drive Gear and 1st Driven Gear Replacement - On Vehicle .