Tools Required

J 21867  Pressure Gage

Important: 

• Before performing a line pressure check, verify that the pressure control (PC) solenoid valve is receiving the correct electrical signal from the PCM.
• Some conditions may be intermittent, therefore this test should be performed at least 3 times.

1. Install a scan tool.
   CAUTION: Keep the brakes applied at all times in order to prevent unexpected vehicle motion. Personal injury may result if the vehicle moves unexpectedly.
2. Start the engine and set the parking brake.
3. Check for a stored Diagnostic Trouble Code (DTC).
4. Repair the vehicle, if necessary.
5. Check the fluid level. Refer to the TRANSMISSION FLUID CHECKING PROCEDURE  .
6. Check the manual linkage for proper adjustment.
   Fig 1: Checking Line Pressure

   Courtesy of GENERAL MOTORS CORP.
7. Turn the engine Off. Remove the oil pressure test hole plug and install the J 21867. 
8. Put the gear selector in PARK range and set the parking brake.
9. Start the engine and allow the engine to warm up at idle.
   NOTE: The total test running time should not be longer than 2 minutes. Running the test longer than 2 minutes may damage the transaxle.
10. Access the PC solenoid valve control test on the scan tool.
11. Increase the PC solenoid actual current from 0 to 1 amps in 0.1 amp increments. Allow the pressure to stabilize for five seconds after each pressure change. Read the corresponding line pressure on the J 21867. 
12. Refer to the LINE PRESSURE  specification table. Compare the data to the table.
13. If pressure readings differ greatly from the table, refer to INCORRECT LINE PRESSURE  .
14. Shut the engine OFF. Remove the J 21867. 
15. Apply sealant GM P/N 12345382 (Canadian P/N 1095348) to the oil pressure test hole plug.
16. Install the oil pressure test hole plug.

Tighten 

Tighten the plug to 12 N.m (106 lb in).