Valve block, function: Diagnostics

The control module performs a valve test each time the ignition is switched on. This test takes place at the same time as the pump-motor test and the valves are actuated for 20 ms.

A DTC is generated if one of the valves malfunctions. The ESP, TCS and ABS functions will be disabled and the warning lamps for the ABS, foot brake, central warning lamp and ESP OFF switched on.