Test Procedure
Use the scan tool to perform the clutch test. Select the following information when setting up the scan tool for running the test. Use the shift transmission feature on the scan tool to complete the clutch test.
- Select - F0: Diagnostics and press ENTER.
- Select - Model Year (i.e., 1 = 2001).
- Select - LDTrk, MPV, Incomplete.
- Select - F0: Powertrain, press ENTER.
- Select - Engine size, press ENTER.
- Select - 5 Speed Automatic, press ENTER.
- Select - F2: Special Functions, press ENTER.
- Select - F1: Transmission Output Controls.
- Select - Shift transmission. This will allow the technician to shift the transmission and check the integrity of each clutch in the transmission.
Attach the transmission pressure gauge as described in line pressure check procedure. See HYDRAULIC PRESSURE TESTS . Apply parking brake and hold service brakes and increase engine speed to 1400 RPM. Using scan tool, select UPSHIFT and shift transmission from 1st gear range sequentially to 5th gear range, while observing turbine speed. Turbine speed should increase momentarily and then drop to zero RPM when each gear range is attained. Line pressure should drop momentarily then regain pressure when each gear range is attained.
Maintain 1400 RPM, select the DOWNSHIFT soft key and downshift transmission from 5th gear range sequentially to 1st gear range while observing turbine speed. Turbine speed should increase momentarily and then drop to zero RPM when each gear range is attained.
To further investigate a suspected leak in a clutch circuit, the clutch test should be repeated keeping engine at idle speed. While performing clutch test at 600 RPM, main pressure should drop momentarily, then regain pressure when each gear range is attained. If main pressure remains low, suspect damaged seal in that gear range. If low pressure is in 1st gear range only, suspect C5 piston seal damage.