Volkswagen Workshop Service and Repair Manuals

Checking exhaust gas recirculation potentiometer -G212-

Special tools and workshop equipment required

t	Adapter cable, 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	Diagnostic cable -V.A.G 1551/3C-

t	Auxiliary measuring set -V.A.G 1594A-

t  Hand multimeter -V.A.G 1526B- t  Current flow diagram Test prerequisites

l  All fuses must be OK. Test procedure

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

–  Connect hand multimeter -V.A.G 1526B- to 6-pin connector contacts 2 and 4. –  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, wire resistance:: max. 1.5 Ω. –  Additionally check wiring for short circuit to one another and short circuit to positive or earth. If the specification is obtained: –  Connect 121-pin adapter cable -V.A.G 1598/31- to engine control unit and reconnect 6-pin connector to exhaust gas recirculation valve -N18-. –  Connect fault reader -V.A.G 1551- or vehicle system tester -1552-. Then switch on ignition and select engine control unit with “Address word 01” → Rep. Gr.01. –  Initiate final control diagnosis and select exhaust gas recirculation valve -N18- → Rep. Gr.01. –  Connect voltage tester -V.A.G 1527B- to test box socket 108 and earth using auxiliary cables from auxiliary measuring set -V.A.G 1594A- or auxiliary measuring set -V.A.G 1594C-. The voltage tester -V.A.G 1527B- must flash. –  Proceed with final control diagnosis until completed. –  Press buttons 0 and 6 for function “End data transfer” and confirm entry with Q button. –  Switch off ignition. –  Renew following components, depending on prerequisite: Voltage tester -V.A.G 1527B- flashes: –  Renew exhaust gas recirculation valve -N18- with exhaust gas recirculation potentiometer -G212-. –  Adapt engine control unit → Rep. Gr.24. If no fault is detected in lines/wiring and the voltage tester -V.A.G 1527B- does not flash: –  Renew engine control unit → Rep. Gr.24.