Drive Links (Drive Link Diagnosis and Test Plan)

Drive links (ABS and ABS/TC)

CAUTION! Danger of accident due to activation of the solenoid valves or the return pump if the vehicle is not stationary!
- Drive links must be activated only when the vehicle is stationary.


NOTE: The following drive links can be activated with the System Tester 2 via the Drive links menu:


Drive links with Solo ABS
- ABS MIL
- Return pump
- Front left ABS solenoid valves via:
Maintain pressure, front left
Reduce pressure, front left
- Front right ABS solenoid valves via:
Maintain pressure, front right
Reduce pressure, front right
- Rear ABS solenoid valves via:
Maintain pressure, rear (rear axle)
Reduce pressure, rear (rear axle)

Drive links with ABS/TC
- ABS MIL
- TC MIL
- TC information light
- TC switch indicator light
- Return pump
- Intake valve
- Switch-over valve
- Front left ABS solenoid valves via:
Maintain pressure, front left
Reduce pressure, front left
- Front right ABS solenoid valves via:
Maintain pressure, front right
Reduce pressure, front right
- Rear left ABS solenoid valves via:
Maintain pressure, rear left
Reduce pressure, rear left
- Rear right ABS solenoid valves via:
Maintain pressure, rear right
Reduce pressure, rear right


NOTE: In the solenoid valve test, it is possible to check both the function and the allocation (test to determine whether electrical or hydraulic lines are swapped).
The test is menu-prompted (observe System Tester Display).

If the selected drive link does not function correctly (reaction) after activation with the Porsche System Tester 2, perform troubleshooting according to the test plan (troubleshooting list) in the following text.

Diagnosis / test plan (troubleshooting) for drive links

Further to MILs and information light
The corresponding MIL or information light (depending on selection) does not flash.

On vehicles with TC, the TC-OFF MIL also flashes when the ABS MIL is activated.

- Check bulb.
- Check wiring from the instrument cluster to the control module according to the wiring diagram.

Further to the return pump

Return pump does not run after activation.
- Perform troubleshooting analogous to test point 12 (diagnostic trouble code 4266). Test Point 12, DTC 4266

Further to front and rear ABS solenoid valves (Maintain pressure and Reduce pressure)

The function of the solenoid valves or the return pump is not OK. If a solenoid valve has a mechanical fault, the fault is not stored in the fault memory.
Hydraulic or electrical lines could be swapped.

If a fault is stored in the fault memory, first eliminate this fault.

Test step "Maintain pressure" not OK:
- Brake pedal not pressed or not pressed at the right time.
- Electrical or hydraulic lines swapped if the activated wheel locks up (precondition: corresponding inlet valve activated with the F8 key).
- Inlet valve faulty.

Test step "Reduce pressure" not OK:
- Brake pedal not actuated.
- If the activated wheel does not alternately lock up and then rotate freely again but another wheel (precondition: the parking brake is not engaged and the selector lever of Tiptronic vehicles is in position "N"), the hydraulic lines are swapped.
- Outlet valve defective.

Further to the intake and switch-over valves (solenoid valves for ABD)

Solenoid valves not OK (function or leakage).


NOTE: A correct test on the ABD solenoid valves is possible only if there is no fault on an ABS inlet valve or ABS outlet valve.

Therefore, read out the fault memory beforehand and remedy this fault first if necessary.

Test step "Intake valve" not OK:
- Test sequence not observed.
- Function of the intake valve not OK.
- Return pump operation not OK. Check pump operation. To do this, select return pump in the Drive links menu (pump must then run).
- ABD secondary circuit poorly bled.
Bleeding (ABS/TC 5.3)
- Intake or switch-over valve leaks.


Test step "Switch-over valve" not OK:
- Test sequence not observed.
- Function of the switch-over valve not OK.