Checking exhaust gas temperature sender 1G235: Audi A3 1.8 (AMK, AMU, APX, APY, …)

🧭 Before you start

Fits: Audi A3 (8L, 1996–2003)

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• Connect up vehicle diagnostic, testing and information systemVAS 5051 with diagnosis leadVAS 5051/1, press vehicle self-diagnosis button and select vehicle system "“01 - Engine electronics”". Engine must be idling.
• The voltage supply for the exhaust gas temperature sender 1G235 is taken from fuel pump relay J17.
• Connect adapter cableV.A.G 1598/31 (test box) to connectors of wiring harness; do not connect engine control unit. Connect earth clip of test box to earth (arrow)24.

🔧 Engine codes this applies to

📐 44 workshop diagrams for AMK

Real factory drawings for this job — timing marks, bolt locations and routing. Locked in the free view.

📋 Procedure

1. Connect up vehicle diagnostic, testing and information system VAS 5051 with diagnosis lead VAS 5051/1, press vehicle self-diagnosis button and select vehicle system "“01 - Engine electronics”". Engine must be idling.
2. From the list (1) select diagnostic function "“08 - Read measured value block”".
3. Press keys 112 on keypad (2) to select "“Display group 112”" and confirm entry by pressing key Q.
4. Check display in zone (1).
5. Increase engine speed.

6. Press the ← key to exit from the function "“08 - Read measured value block”".
7. Press function "“06 - End output”".
8. Switch off ignition and unplug diagnostic connector. [Note: The voltage supply for the exhaust gas temperature sender 1G235 is taken from fuel pump relay J17.]
9. Remove cover in front of intake manifold.
10. Unplug electrical connector (arrow) at exhaust gas temperature sender 1G235.
11. Connect voltage tester V.A.G 1527 B between contact (3) of connector for exhaust gas temperature sender 1G235 and earth "“–”".
12. Operate the starter briefly.
13. Check for open circuit in wiring from contact (3) of connector for exhaust gas temperature sender 1G235 via fuse to fuel pump relay J17.
14. Repair wiring connection if necessary.
15. Connect adapter cable V.A.G 1598/31 (test box) to connectors of wiring harness; do not connect engine control unit. Connect earth clip of test box to earth (arrow)24.
16. ⚠ To prevent damage to electronic components, select appropriate measuring range before connecting measuring leads and observe test requirements. — Check for open circuit and short to positive or earth in the following wiring:
17. Repair wiring connection if necessary.
18. Renew exhaust gas temperature sender 1G235.

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