Checking exhaust gas recirculation — AUDI

🧭 Before you start

Fits: platform codes 70A, 70B, 70C, 70E, 70H, 70J, 70K, 70L, 70M, 7DA, 7DB, 7DC, 7DE, 7DH, 7DJ, 7DK, 7DL, 7DM

• Special tools named: V.A.G 1551

Don't miss

• If a constant value of 550 mg/H (fixed substitute value) is displayed in display zone 3, check air mass meter G70.
• At room temperature the resistance is in the lower tolerance range, and at operating temperature in the upper tolerance range.
• If necessary, left headlight may have to be released and placed to side to connect test boxV.A.G 1598/31Electrical system; Rep. Gr. 94; Lights, bulbs, switches - exterior.

🔧 Engine codes this applies to

📋 Procedure

1. Connect fault readerV.A.G 1551 and select engine electronics control unit with "“address word 01”". When doing this the engine must be running at idling speed Rep. Gr. 01; Self-diagnosis; Connecting fault reader V.A.G 1551 and selecting engine electronics control unit
2. Press keys 0 and 4 for function "“Initiate basic settings”" and confirm entry with Q key.
3. Press keys 0, 0 and 3 for "“Display group number 3”" and confirm entry with Q key. [Note: If a constant value of 550 mg/H (fixed substitute value) is displayed in display zone 3, check air mass meter G70.]
4. Specification: Display zone 3 370… 510 mg/stroke
5. Specification: Display zone 4 0… 5 %

6. Specification: Display zone 3 140… 300 mg/stroke
7. Specification: Display zone 4 95… 100 %
8. Specification: Display zone 3 300...490 mg/stroke
9. Specification: Display zone 4 0… 5 %
10. Specification: Display zone 3 160… 270 mg/stroke
11. Specification: Display zone 4 95… 100 %
12. Specification: Display zone 3 300… 490 mg/stroke
13. Specification: Display zone 4 0… 5 %
14. Specification: Display zone 3 160… 270 mg/stroke
15. Specification: Display zone 4 95… 100 % [Note: Displays in display zone 3 are pressure-dependent and therefore elevation-dependent. The specified values refer to 0 m MSL. If the measured values deviate greatly due to the altitude, check whether a specification difference of min. 100 mg/H is achieved between displays for EGR.active and EGRn.active in display zone 3.]
16. Check mechanical exhaust gas recirculation valve Rep. Gr. 26; Exhaust gas recirculation system; Checking exhaust gas recirculation valve
17. Check exhaust gas recirculation valve N18 as follows:
18. Press → key.
19. Press keys 0 and 6 for function "“End data transfer”" and confirm entry with Q key.
20. Switch off ignition.
21. Pull connector (2) off exhaust gas recirculation valve (1).
22. Measure resistance at valve. Specification: 14…18 Ω [Note: At room temperature the resistance is in the lower tolerance range, and at operating temperature in the upper tolerance range.]
23. Renew exhaust gas recirculation valve N18.
24. Switch on ignition.
25. Measure supply voltage at valve connector contact 1 and at engine earth. Specification: approx. battery voltage
26. Switch off ignition.
27. Connect test boxV.A.G 1598/31 to control unit wiring harness. [Note: If necessary, left headlight may have to be released and placed to side to connect test boxV.A.G 1598/31Electrical system; Rep. Gr. 94; Lights, bulbs, switches - exterior.]
28. Check lines/wiring between test boxV.A.G 1598/31 and connector for open circuit referring to current flow diagram. Contact 1 + sockets 1 and 2 Contact 2 + socket 61 Line resistance: max. 1.5 Ω
29. Also check wiring for short to one another, short to vehicle earth and short to battery positive. Specification: ∞ Ω
30. Renew diesel direct injection system control unit J248

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