ground points are shown on the wiring diagram Ground points.
- plus (vehicle voltage) is connected to control module connector PIN 17 and PIN 18.
- Use the System Tester 2 to test the function of the ABS solenoid valves via the Drive links menu (reaction at the front left, front right, rear left
and rear right wheels).
If the reaction is not OK, check the hydraulic allocation (text below).
Allocation test using example of left front wheel:
- In the Drive links menu, sub-menu Reduce pressure, front left, the left front wheel must alternately lock up and then rotate freely (also
see P.45 - D 35/36).
- The allocation is wrong if the activated wheel does not alternately lock up and rotate freely again, but a different wheel does this instead.
- The hydraulic unit must be replaced if the aforementioned drive link test is not OK but the hydraulic lines are not not swapped.
Test Point 11
TEST POINT 11
Valve Supply Voltage
DTC 4276
The System Tester 2 can be used to determine whether the valve relay has picked up or dropped out. Select 'Valve relay" in the Input signals
menu. 'Valve relay picked up" or 'Valve relay dropped out" then appears in the Tester display.
Required display: Valve relay picked up.
If the control module connector was pulled off, first switch off the ignition before the test and then switch it on again, as the valve relay will
otherwise not pick up.
The valve relay also can be in the dropped~ut state if there is another system fault. (ABS valve fault.)
The complete hydraulic unit with integrated valve relay must be replaced if the valve relay is damaged.
Important: Before replacing the hydraulic unit, check whether:
- ground is connected to control module connector PIN 16 (from ground point 2) and PIN 19 (from electronics ground). The locations of the
ground points are shown on the wiring diagram Ground points. See: Brakes and Traction Control/Antilock Brakes / Traction Control
Systems/Locations/Ground Locations
- plus (vehicle voltage) is connected to control module connector PIN 17 and PIN 18.
If all test steps are OK, replace the hydraulic unit.
Test Point 12
TEST POINT 12
Return Pump Fault
DTC 4266
Fault effect: No feedback signal (return-pump monitoring) to the control module.
The Porsche System Tester 2 can be used to test the function of the return pump via the Drive links menu.
To do this, call up the return pump in the Drive links menu and activate the pump (required function: return pump runs).
The complete hydraulic unit must be replaced if the return pump is damaged.