For 1990-2009 cars

# Service Manual Update for Automatic Transaxle Oil Pump Output Test and/or Line Pressure Test

Subject: | Service Manual Update for Automatic Transaxle Oil Pump Output Test and/or Line Pressure Test

Models: | 1991 - 1997 Saturns equipped with MP6/MP7 automatic transaxles

### Purpose

When diagnosing a condition and instructed to perform a pressure test according to the service manual, perform the procedure on the following two pages.

Important: The following two tests, located in the service manuals, should never be used when a pressure test is required.

• | "Oil Pump Output Test," located in the 1995, 1996 and/or 1997 "Automatic Transaxle Service Manual."

• | "Pressure Test in Drive at Idle," located within the "Line Pressure Test," of the "1991-1994 Automatic Transaxle Service Manual."

Instead of using either of these two tests located in the service manuals, refer to the following tests contained within this bulletin.

### Line Pressure Test

1. Run engine to bring transaxle to running temperature of 70°C (158°F).
2. Remove transaxle fluid temperature sensor and install pressure gauge.
3. Connect the Scan tool.
4. Key On engine Off. On first menu selection, select "Special Test."
5. Select Line Pressure.
6. Transaxle in Park.
7. Scan tool will prompt you to start engine.
8. Select Run and the test will begin. The test will set engine speed to 1500 rpm and command line pressure up in steps from 396 - 1518 kPa (57-220 psi) in 100 kPa (15 psi) intervals.
9. As test is in progress, watch the gauge to assure the gauge readings follow the commanded pressures.
10. Oil pressure maximum and minimum values at idle should be checked using the following procedure:

Important: For delay to reverse or harsh reverse engagement conditions, it is important to have at least 1206 kPa (175 psi) in Park at 70°C (158°F) to ensure proper pressure regulator and pump operation.

• | With gauge 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 (7.5 amp TRS LP) UHJB

• | With engine idling in P (Park), pressure should be 1206-1690 kPa (175 -245 psi)

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

| Important: With engine in Park, and the 7.5 amp TRS LP line pressure fuse removed, minimum pressure should be 1206 kPa (175 psi). This is a change from previously published service manual.

11. 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 nut to 8 N·m (71 in -lbs)

Command Line Pressure | Gauge Readings Should be in this range
kPa | psi | kPa | psi
396 | 57 | 400-500 | 58-72
498 | 72 | 425-550 | 61-80
600 | 87 | 500-675 | 72-98
702 | 102 | 600-800 | 87-116
804 | 117 | 700-925 | 101-134
906 | 131 | 800-1050 | 116-152
1000 | 146 | 900-1175 | 130-170
1110 | 161 | 1000-1300 | 145-188
1212 | 175 | 1100-1400 | 159-203
1314 | 191 | 1200-1500 | 174-218
1416 | 205 | 1300-1650 | 188-240
1518 | 220 | 1500-1850 | 218-268