Control Unit Function

Control Unit Function

Replace Control Module

CAUTION:
Risk of damage due to corrosion in the plug connections.

This may cause malfunctions and system failures.
- When removing the hydraulic unit, disconnecting the plug must be the fast step.
- Protect the plug connections from liquids.
- Remove any penetrating liquids completely by suitable means.
- When installing the hydraulic unit, connecting the plug must be the first step.

If the control module is damaged, the complete hydraulic unit with integrated control module must be replaced. Observe the following points:
- The control module must be coded for the corresponding type of transmission (manual transmission/Tiptronic).
- The Vehicle Identification Number must be entered.
- A static test and the swap test must be performed with Porsche System Tester II No. 9588.

Static Test

NOTE: This test must be carried out after the hydraulic unit has been exchanged.

This test involves carrying out the valve and pump motor test. The test is normally not started until the vehicle moves off (speed > 6 km/h (3.75 mph)). The test includes actuating all ABS valves and the pump motor and checking their feedback. It only makes sense to carry out the "Static test" function if no fault has previously been detected as present, i.e. the system is not switched off.

PROCEDURE:
1. Read out the fault memory with the Porsche System Tester II No. 9588 and remedy the entered faults.
2. Select the 'Static test' menu item.
3. Switch ignition off.
4. Switch ignition on.
5. Wait until the 'Fault memory' display appears and, if necessary, remedy the entered faults.
6. After successfully remedying the faults, perform the test again as from Step 2.

Swap Test

NOTE: This test must be carried out after the hydraulic unit has been exchanged.

The swap test is used to check the allocation of the brake pressure lines to the wheel brake cylinders. A hydraulic and an electrical test are carried out.

PROCEDURE:

NOTE: If a question is answered with No, the Porsche System Tester II No. 9588 will abort the test.

1. Using the Porsche System Tester II No. 9588, select the menu item 'Swap test'.
2. Using the up arrow and down arrow keys, select an area (e.g. 'Hydraulics, front left').
3. Then press the F8 'Start' key.
4. Press the >> key, then actuate the brake and keep it actuated during the entire test.
5. Then press the >> key. Check whether the front left wheel can be turned while all the others are blocked. Confirm with the relevant key Yes/No and the >> key.
6. Check whether all the wheels are now blocked. Confirm with the relevant key Yes/No and the >> key.
7. Check whether the front left wheel can now be turned while all the others are blocked. Confirm with the relevant key Yes/No key.
8. Check whether all the wheels are now blocked. Confirm with the relevant key Yes/No and the >> key.
9. Release the brake and continue with Step 2 in a different area.