GM DCT service manual flush process :

There are two procedures that must be performed before and after changing the DCT filter. And the level check procedure is correct as well.

Before changing the filter:
Quote:
Hydraulic System Flush Procedure Diagnostic Instructions

• Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle
• Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis

Description
This procedure is used to flush the transmission fluid through the filtration system before a repair is performed that may have been caused by debris in the fluid.

The following will occur when the scan tool control is enabled: Engine Speed = 2,000 RPM & Line Pressure = Increase — For 8 min
When to Perform the Procedure
Note: Do NOT perform this procedure unless directed here from another procedure.

Perform this procedure before servicing the component: T12 Automatic Transmission
Conditions for Running the Procedure
• DTCs related to the following system/component = Not Set
o K71 Transmission Control Module
o T12 Automatic Transmission
• Brake Pedal = Applied
• Engine = Running
• Transmission Fluid Temperature Sensor = Warmer than 50°C (122°F)
• Transmission Range = P or N
• Vehicle Speed = 0 km/h (0 MPH)
Reference Information Scan Tool Reference Control Module References
With Scan Tool
Note: Do NOT perform this procedure unless directed here from another procedure.
1. Ignition » On / Vehicle » In Service Mode
2. Select: Module Diagnostics
3. Select: K71 Transmission Control Module
4. Select: Configuration/Reset Functions
5. Select: Hydraulic System Flush Procedure
6. Follow the instructions on the scan tool. The procedure will complete within 8 min
Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification
After the filter change:
Quote:
Hydraulic System Leak Test Diagnostic Instructions
• Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle
• Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis

Description
This procedure is used to test the transmission for leaks after a repair.

The following will occur when the scan tool control is enabled: Engine Speed = 2,000 RPM & Line Pressure = Increase — For 1 min
When to Perform the Procedure Note: Do NOT perform this procedure unless directed here from another procedure.

Perform this procedure when the following component has been serviced: T12 Automatic Transmission
Conditions for Running the Procedure
• DTCs related to the following system/component = Not Set
o K71 Transmission Control Module
o T12 Automatic Transmission
• Engine = Running
• Transmission Fluid Temperature Sensor = Warmer than 50°C (122°F)
• Transmission Range = P or N
• Vehicle Speed = 0 km/h (0 MPH)
Reference Information Scan Tool Reference Control Module References
With Scan Too
Note: Do NOT perform this procedure unless directed here from another procedure.
1. Ignition » On / Vehicle » In Service Mode
2. Select: Module Diagnostics
3. Select: K71 Transmission Control Module
4. Select: Configuration/Reset Functions
5. Select: Hydraulic System Leak Test
6. Follow the instructions on the scan tool. The procedure will complete within 1 min
Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification
Fluid level check:

Quote:
Transmission Fluid Level and Condition Check
Fluid Level Check Procedure Warning:
The transmission fluid level must be checked when the transmission fluid temperature (TFT) is between 20–40°C (68–104°F). If the TFT is not within this range, either idle or brake torque the vehicle to raise the fluid temperature, or shut off the vehicle to allow the fluid to cool as required.
Setting the fluid level with a TFT outside this range will result in either an under or over-filled transmission.

TFT greater than 40°C=under-filled, TFT less than 20°C=over-filled.
An under-filled transmission will cause premature component wear or damage.
An over-filled transmission will cause fluid to discharge out the vent tube, possibly causing a fire that may result in serious bodily injury or severe vehicle damage, fluid foaming, or pump cavitation.

1. Start and idle the engine with the A/C turned off.
2. Run the vehicle for 3 to 5 minutes while selecting drive and reverse to fill the clutch circuits.
To properly fill the circuits, place foot on brake, shift into drive for 30 to 45 seconds then shift into reverse for 30 to 45 seconds then repeat.
3. Stop the engine and perform the following actions within 5 minutes after stopping the engine.
4. Raise the vehicle on a hoist. The vehicle must be level with the shift selector in PARK range. Lifting and Jacking the Vehicle
5. Note: To avoid rounding of the transmission oil filler plug, it is recommended using an appropriate 6 point metric socket or wrenches.

Caution:
Use Fuchs TITAN EG FFL-4 TREMEC transmission fluid only.
Failure to use the proper fluid may result in transmission internal damage.

Note:
6. During transmission manufacturing, the fluid is filled by volume and therefore, it could have a fluid level that is approximately 13 mm (0.5 in) below the transmission oil filler plug.
7. If more than 1 liter (1.06 quarts) of fluid drains from the transmission, the transmission may have been previously filled for track use.
8. Note: To avoid rounding of the transmission oil filler plug, it is recommended using an appropriate 6 point metric socket or wrenches.
9. Place a suitable drain pan under transmission.
10. Transmission Oil Filler Plug (1) » Remove — Transmission Oil Filler or Drain Plug Replacement
11. Fill or drain oil until oil level is at the bottom edge of the fill opening.
12. Transmission Oil Filler Plug (1) » Install — Transmission Oil Filler or Drain Plug Replacement