Volkswagen Workshop Service and Repair Manuals > Golf Mk4 > Power unit | 4-cylinder injection engine (5-valve) | Mixture preparation system, electronic inj.,Gas | Checking components | Reading and erasing engine control unit fault memory

Reading and erasing engine control unit fault memory

Special tools and workshop equipment required

t	Vehicle diagnosis, testing and information system -VAS 5051B-

t	Diagnosis cable -VAS 5051/5A-

Procedure

–	Connect vehicle diagnosis, testing and information system -VAS 5051B- as follows:

–	Pull cover -1- off in -direction of arrow-.

–	Connect diagnosis cable -VAS 5051/5A- to diagnostic connection.

–	Start engine and run at idling speed.

Only if engine does not start:

–	Switch on ignition.

Select operating mode:

–	Press key on display for “Vehicle self-diagnosis”.

Select vehicle system:

–	Press key “01 - Engine electronics” on display.

The control unit identification and coding are indicated on the display.

Select diagnostic function:

–	Press key “02 - Read fault memory” on display.

–	If no fault is stored in engine control unit “0 fault(s) detected” is displayed.

–	If faults are stored in the engine control unit, these are shown one below the other on the display.

–	Press the ← key.

–	Press button “05 - Clear fault memory” on display.

–	Press function “06-End output”.

Volkswagen Workshop Service and Repair Manuals