Checking potentiometer for exhaust gas recirculation (G212) — VW

AHW AUA AUB APE AQQ
Special tools, workshop equipment, test and measuring appliances and auxiliary items required

V.A.G 1598/31 Test box
V.A.G 1527 B Diode test lamp
Fault reader V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3
V.A.G 1594 A Adapter set
V.A.G 1526 Hand multimeter
Current flow diagram

Test conditions

Fuse SB30 must be OK.

Test sequence

Pull 6-pin connector (black) off EGR valve => Page
26-22
, item
12

Connect multimeter to contacts 2 and 4 of 6-pin connector for voltage measurement.
Switch on ignition.
Specification: min. 4.5 V

If the specification is not attained:

Switch off ignition.

Connect test box V.A.G 1598/31 to control unit wiring harness. The engine control unit remains disconnected.

Check wiring for open circuit between test box and 6-pin connector using current flow diagram.
Contact 2 and test box socket 98
Contact 4 and test box socket 108
Contact 6 and test box socket 100
Wire resistance: max. 1.5ω
Additionally check wiring for short to one another, and for short to positive or earth.

If the specification is obtained:

Connect engine control unit to test box V.A.G 1598/31 and reconnect 6-pin connector to EGR valve.
Connect the fault reader V.A.G 1551 (V.A.G 1552). Then switch ignition on and select engine control unit with the "Address word" 01.

=> Repair group 01; Self-diagnosis general: Connecting fault reader V.A.G 1551 and selecting engine electronics control unit.
4-Cyl. injection engine (4-valve, roller rocker arm), Mechanics
Self-diagnosis general: Connecting fault reader V.A.G 1551 and selecting engine electronics control unit.

Initiate final control diagnosis and select EGR valve (N18):

=> Repair group 01; Final control diagnosis; Performing final control diagnosis
4-Cyl. injection engine (4-valve, roller rocker arm), Mechanics
Final control diagnosis
Performing final control diagnosis

Connect diode test lamp V.A.G 1527 B to test box socket 100 and earth using adapter from V.A.G 1594.
The LED must flash.
Proceed with final control diagnosis until completed.
Press keys 0 and 6 for the "End data transfer" function and confirm input with the Q key.
Switch off ignition.
Depending on conditions, renew following components:

LED flashes:

Renew EGR valve (N18) with potentiometer (G212).

Erase learnt values and re-adapt engine control unit

=> Repair group 24; Engine control unit; Erasing learnt values and adapting engine control unit to throttle valve control part and EGR valve
4-Cyl. injection engine (4-valve, roller rocker arm), Mechanics
Engine control unit
Erasing learnt values and adapting engine control unit to throttle valve control part and EGR valve

If no wiring fault is detected and the LED does not flash:

Renew engine control unit.

=> Repair group 24; Engine control unit; Renewing engine control unit
4-Cyl. injection engine (4-valve, roller rocker arm), Mechanics
Engine control unit
Renewing engine control unit