Checking air mass meter G70: VW Golf IV / Bora (AGP, AGR, AHF, ALH, …)

🧭 Before you start

Connect the fault reader, read display group 10 at idle and compare with 230...370 mg/stroke, checking EGR if out of range. Road test in 3rd gear at full throttle and confirm over 800 mg/stroke. If the meter fails, end data transfer, unplug G70, check its voltage supply with ignition on, then test the wiring to J248 with the adapter for open and short circuits before renewing G70 or J248.

Fits: VW Golf IV / Bora (1J)

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• Secure the fault reader on the rear seat and operate it from there during the road test.
• Check exhaust gas recirculation before condemning G70 on a low idle reading.
• At full throttle display zone 4 must read 100 % for the test to be valid.
• Check wiring for shorts to earth, battery positive and each other, not just open circuits.

Written for this job from the workshop steps below · TorqFix editorial.

🔧 Engine codes this applies to

📋 Procedure

1. Connect fault readerV.A.G 1551 or vehicle system testerV.A.G 1552 and select control unit for engine electronics with "“address word 01”". Engine must be idling. (Connect fault reader and select engine electronics control unit .)
2. ⚠ Secure fault reader to rear seat and operate from this position. — Press keys 0 and 8 for function "“Read measured value block”" and confirm entry with Q key.
3. Press keys 0, 1 and 0 for "“Display group number 10”" and confirm entry with Q key.
4. Observe display in display zone 1.
5. Specification: 230...370 mg/stroke

6. Check exhaust gas recirculation 4-cyl. diesel engine, mechanics26Checking exhaust gas recirculation system
7. Accelerate vehicle in 3rd gear from approx. 1500 rpm using full throttle.
8. At approx. 3000 rpm, press PRINT button on fault readerV.A.G 1551.
9. Specification in display zone 4: 100 % (accelerator pedal position)
10. Repeat test and accelerate vehicle at full throttle.
11. Specification in display zone 1: above 800 mg/stroke (air mass drawn in).
12. Renew air mass meter G70.
13. Press → button.
14. Press keys 0 and 6 for function "“End data transfer”" and confirm entry with Q key.
15. Switch off ignition.
16. Separate connector for air mass meter G70.
17. Switch on ignition.
18. Measure voltage supply for air mass meter G70 between following connector contacts:
19. Measure voltage supply for air mass meter G70 between following connector contacts:
20. Switch off ignition.
21. Connect adapterV.A.G 1598/22 to control unit wiring harness.
22. Check wiring between adapter and connector for open circuit using current flow diagram. Contact 1+socket 50 Contact 2+socket 25 Contact 3+socket 2 and 28 Contact 5+socket 1 and 27 Contact 6+socket 52
23. Check wiring between adapter and connector for open circuit using current flow diagram. Contact 2+socket 2 and 28 contact 3+socket 4 contact 4+socket 50 contact 5+socket 52.
24. Also check wiring for short to one another, short to vehicle earth and short to battery positive.
25. Renew diesel direct injection system control unit J248

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