Test Point 1

DTC 11

Transverse Lock Valve

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 transverse lock solenoid valve) and localize the discontinuity by reference to the wiring diagram.





2. Pull off valve relay (No. 1) on the hydraulic unit. (Remove wheel housing cover at the front-left side).

Check for a short circuit to plus or ground in the wiring path, as described in point 1, by measuring at PIN 21.

If there is a fault in the wiring path, separate it as described in point 1 so that the unwanted connection to the positive or negative side can be located.





3. Measure the internal resistance of the transverse lock valve. For this purpose, disconnect the plug connection on the transverse lock solenoid valve (arrow). The transverse lock solenoid valve is located beneath the rear left wheel housing cover. Nominal value 2...4 ohms between the PINs on the valve block.

Nominal value not OK: Replace the transverse lock solenoid valve.

4. Check that the valve relay is energized (voltage present at solenoid valves of ABS and PSD).

Connect all plugs and the relay for this purpose. Push back the protective tube on the transverse lock valve plug (in the wheel housing on the rear left). Switch off the ignition, then switch it on again. Battery voltage must be present at the black wire.

If no battery voltage is present: Continue with Test Point 13/DTC 34 (valve relay). Note testing instructions (see below).

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

Notes On Testing

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.