Checking the elements of the exhaust gas recirculation system

On 1Y engine

1. Start the engine and let it idle.

2. The EGR valve diaphragm should move towards the tube fitting (can be identified by touch below the arrow) (pic. 6.62). Exhaust gases are recirculated.



3. Increase the speed above 3200 rpm, while the exhaust gas recirculation should turn off (the membrane moves towards the exhaust manifold).

4. If the EGR system is not working properly, check the EGR valve. For this:

• turn off the ignition;
• disconnect the two-pin wiring connector 2 from the EGR valve 1 (pic. 6.63);
• connect the diode tester VAG 1527 using auxiliary wires from VAG 1594 to the connector pins;
• start the engine and let it idle - the tester lamp should light up;
• increase the speed above 3200 rpm - the tester lamp should go out.

5. If the lamp does not light up or goes out as expected, check the wiring according to the wiring diagram or replace the preheating control unit if necessary.


6. If the light comes on or goes off as expected, check the EGR valve.

Engines AEY, ANV, AKW

7. Turn off the ignition.

8. Disconnect the wiring connector from the EGR valve.

9. Measure the resistance between the valve contacts (pic. 6.64). Specification value: 14-18 ohms.



10. If specification is not reached, replace EGR valve.

11. If the specification value is reached:

On vehicles with a 68-pin control unit wiring connector

• Connect the VAG 1598/18 tester to the engine control unit wiring harness (rice. 6.54);
• Check the wire between the tester and the connector for an open circuit; pin 1 and slot 68, pin 2 and slot 25 (pic. 6.65). Set value; 1.5 ohm;
• additionally check the wires for shorting one to the other, to «mass» vehicle and to the positive pole of the battery. Specification resistance: ∞ Ohm.

On vehicles with 80-pin control unit wiring connector

• Connect the VAG 1598/22 tester to the engine control unit wiring harness (rice. 6.56);
• Check the wire between the tester and the connector for an open circuit: pin 1 and slot 28. pin 2 and slot 29 (pic. 6.65). Set value: 1.5 ohm;
• Additionally, check the wires for shorting one to the other, to «mass» vehicle and to the positive pole of the battery. Specification resistance: ∞ Ohm.

For all vehicles

12. If no fault is found in the wires, then replace the engine control unit.