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Checking Lambda probe heating for Lambda probes after catalytic converter — VW

Checking Lambda probe heating for Lambda probes after catalytic converter on VW: 17 steps, engines AZX.

Workshop procedure for VW — the exact step sequence and torque figures, straight from real workshop data.

17 steps 1 engine code

🧭 Before you start

Fits: VW Passat B5 (3B)

  • Special tools named: V.A.G 1551, V.A.G 1552, V.A.G 1598/31
  • Renewed: lambda probe

Don't miss

  • Lambda probe heating may be switched on or off depending on the engine's operating status, i.e. the displays in display zone 4 may show either Htg.b(a)C.ON or alternatingly Htg.b(a)C.ON/Htg.b(a)C.OFF.

🔧 Engine codes this applies to

AZX

📋 Procedure

  1. Connect fault reader V.A.G 1551 (V.A.G 1552). Start engine and select "“Address word”" 01 of engine control unit. (Connect fault reader and select engine control unit )
  2. Press keys 0 and 8 for function "“Read measured value block”" and confirm entry with Q key.
  3. Press keys 0, 4 and 1 for "“Display group number 41”" and confirm entry with Q key.
  4. Check specification for Lambda probe heating in display zone 4. [Note: Lambda probe heating may be switched on or off depending on the engine's operating status, i.e. the displays in display zone 4 may show either Htg.b(a)C.ON or alternatingly Htg.b(a)C.ON/Htg.b(a)C.OFF.]
  5. Press → button.
AZX? Steps differ between engine variants — check this job against your exact car before you commit to it. Check my car — free →
  1. Press buttons 0 and 6 for function "“End output”" and confirm entry with Q button.
  2. Switch off ignition.
  3. Disconnect 4-pin connector (brown) (2) to Lambda probe after catalytic converter G130.
  4. Set multimeter to resistance measurement and check resistance of probe heating at connector to Lambda probe between contacts 1+2; specification: 8.0...20.0 Ω
  5. Renew Lambda probe after catalytic converter G130.
  6. Connect multimeter using auxiliary cables fromV.A.G 1594 to measure voltage at contacts 1+2 (connector to engine control unit).
  7. Start engine and run at idling speed.
  8. Measure voltage supply and observe display group 41, display zone 4.
  9. Switch off ignition.
  10. Connect test box V.A.G 1598/31 to control unit wiring harness. The engine control unit remains disconnected.
  11. Check line between test box and 4-pin connector for open circuit referring to current flow diagram. Contact 2+socket 63 Line resistance: Max. 1.5 Ω
  12. Check line between 4-pin connector contact 1 and fuel pump relay J17 for open circuit using current flow diagram. Cable resistance: max. 1.5 Ω.

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TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.

The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.

Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.

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Workshop data on this page last updated 20 Sep 2026.