Brake bleeding solved with Ista-D

[Maxi840ci]

2006 E53 4.4
If you ever get air in the ABS, seems impossible to remove without bmw software. I managed to get ista-D installed. Once connected, the correct function is under "vehicle management/service functions/Chassis/DSC8/brake bleeding routine/" then on right select "ABL Brake Bleeding Procedure". Then click "continue" and it will activate the ABS pump and cycle through the values. I did the passenger-rear first and tons of air came out the first time using the software. So much air I though the reservoir was dry. I was using a homemade pressure bleeder on the reservoir at ~5 to 10psi. pressure is essential. after running the routine with the bleeder open, pump the brake to the floor 5 times to clear the air. make sure bubble free and then close the bleeder valve. move to the next line.


At first I tried "vehicle information/control unit tree/DSC" and the "call up ECU functions", then "activate pump" or something like that. This option does turn the pump on for 5 seconds, but it does not seem to cycle through valves. I tried this way 2 times and the pedal was still mushy. The correct approach is through the "service function" menu, which makes sense.

Some images from ISTA:

https://photos.app.goo.gl/Tuzn3MPcjVdkgtCB7
https://photos.app.goo.gl/RaZTe613UrtmNyRj8


From the software:

Primary circuit: In the DSC hydraulic control unit, air bubbles can adhere to the edges and valves, and these cannot be removed by rinsing with the brake fluid change unit. The vibrations that occur during ventilation with the diagnosis system loosen the air bubbles.

Secondary circuit: Under normal conditions (DSC does not intervene), the secondary circuit of the DSC hydraulic control unit is closed, so that the air it contains cannot escape when rinsing with the brake fluid change unit. When bleeding with the diagnosis system, the return pump and the exhaust and high-pressure switching valves are activated during rinsing so that the secondary circuit is also bled.

After the exchange and repair of the following components, bleeding must be done with the diagnosis system:
- Hydraulic unit

- Master Brake Cylinder

- Components or connection lines that are located between the hydraulic unit and tandem brake master cylinder


Operations:
For the DSC8, the operations 3 ... 7 must be performed in the order rear right, rear left, front right and front left.

For the DSC Mk60 the operations are specified explicitly in the test module.

1. Connect the brake fluid-change unit and switch on (the filling pressure must not exceed 2 bar)

2. Fully rinse the brake system

3. Attach the bleeder container to the vent valve

4. Open vent valve

5. Start bleeding with the diagnosis system with open vent valve

6. After completing the bleeding, operate the brake pedal 5 times to the limit position; bubble-free brake fluid must escape

7. Close vent valve

8. Remove the brake fluid change unit

Note:
A second person is required for this task