ABS/ASC 5

General

The ABS/ASC 5 has self-diagnosis capabilities. The following diagnosis functions are possible:

• Read identification
  
• Read out input signals
  
• Read out / delete defect code memory
  
• Activate components
  
• Read coding data
  

Diagnosis communication takes place via a bi-directional diagnostic link (single-wire interface).

Important!

The ABS/ASC control unit features a non-volatile defect code memory. In warranty cases, print out test code and do not delete defect code memory!

Defect Code Memory

Under certain conditions, speed sensor defects may be stored in the defect code memory although there is no defect. This is the case for conditions under which there is no plausible operating status for the control unit.

Under these conditions, two or three speed sensor faults with the same ambient storage conditions are stored in the defect code memory.

The following causes are possible:

• Wheels balanced with a finish balancer (ignition lock position 2)
  
• Towing on one axle (ignition lock position 2)
  
• Operation on a high-speed roller dynamometer tester
  

During diagnosis, the defect code memory is not updated before the ignition is switched off and then switched on again.

Activate components

Components cannot be activated in the case of a current defect ("current defect"). There is no feedback to the control unit indicating whether activation was successful.