Volkswagen Workshop Service and Repair Manuals

Checking exhaust gas recirculation potentiometer -G212-

Special tools and workshop equipment required

t	Adapter lead, 121-pin -V.A.G 1598/31-

t	Voltage tester -V.A.G 1527B-

t	Fault reader -V.A.G 1551- or vehicle system tester -V.A.G 1552-

t	Diagnosis cable -V.A.G 1551/3C-

t	Adapter set -V.A.G 1594A-

Not illustrated: t  Current flow diagram Test prerequisites

l  The fuses 10, 28, 29, 34 and 43 must be in order. Test procedure

–  Pull 6-pin connector -1- (grey) off exhaust gas recirculation valve -N18-.

–  Connect multimeter to measure voltage to contacts 2 and 4 of 6-pin connector. –  Switch on ignition. Specification: at least 4.5 V If the specification is not attained: –  Switch off ignition.

–  Connect 121-pin adapter cable -V.A.G 1598/31- to control unit wiring harness. The engine control unit remains disconnected.

–  Check wiring between test box and 6-pin connector for open circuit referring to current flow diagram. Contact 2 and test box socket 96, contact 4 and test box socket 84, contact 6 and test box socket 108 wiring resistance: max. 1.5 Ω. –  Additionally check wiring for short circuit to one another as well as short circuit to positive and earth. If the specification is attained: –  Also connect 121-pin adapter cable -V.A.G 1598/31- to engine control unit and reconnect 6-pin connector to exhaust gas recirculation valve. –  Connect fault reader -V.A.G 1551- (vehicle system tester -V.A.G 1552-). Then switch ignition on and select engine control unit with “Address word” 01. → Rep. Gr.01 –  Initiate final control diagnosis and select activated charcoal filter solenoid valve -N18-: → Rep. Gr.01. –  Connect voltage tester -V.A.G 1527B- to test box socket 108 and earth using adapter cables from adapter set -V.A.G 1594A-. The LED must flash –  Proceed with final control diagnosis until completed. –  Press keys 0 and 6 for function “End data transfer” and confirm entry with Q key. –  Switch off ignition. –  Renew following components, depending on conditions: LED flashes: –  Renew exhaust gas recirculation valve -N18- with exhaust gas recirculation potentiometer -G212- –  Erase learnt values and adapt engine control unit again → Rep. Gr.24. If no fault in wiring is detected and the LED does not flash: –  Renew engine control unit → Rep. Gr.24.