Possible Causes Elimination Remarks

1: Lateral lock valve

Fault code -11-

No feedback signal from valve to control unit

1. Switch off the ignition. Pull the plug off the control unit. Check that circuits at plug are not interrupted.

PIN 21 to PIN 23 PIN 21 to PIN 17

If necessary, Interrupt the wiring path (plug on locking valve block) and localize the break by reference to the circuit diagram.

2. Pull off valve relay (No. 1) at hydraulic unit. Check for a short to positive or earth/ground in the wiring path as described in Item 1, by measuring at PIN 21. If there is a fault in the wiring path, separate it as described in Item 1 so that the unwanted connection to the positive or negative side can be localized.


3. Measure the internal resistance of the lateral locking valve. Desired value 2...4 Q between PIN 1 and PIN 3 on valve block. If desired value is incorrect: renew the valve block.

911 Carrera 4 All-Wheel Drive / Antiblock System

Fault, Fault Code Possible Causes, Elimination, Remarks


4. Check that the valve relay is energized (current present at solenoid valves).

Attach all plugs and relays. Push back the protective cap at the valve block plug.

Switch off the ignition, then switch it on again.

The car's elec. system voltage must be present at PIN 1 and PIN 2.

If no voltage is present: proceed with fault code - 34 - (valve relay). Note testing instructions (see below).

If a voltage is present, try replacing the PDAS/ABS control unit (output stage defective).

If a plug for the power supply to the solenoid valves (ABS or differential lock) is detached while the ignition is switched on, the valve relay is de-energized. Even if the plug is then reconnected, the relay will not be re-energized until the ignition has been switched off and on again.

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

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