Checking throttle valve control module: VW Passat B5 2.3 (AZX)

🧭 Before you start

Read display group 62 with the ignition on and check both throttle angle senders at the idle stop and through to full throttle. If out of spec, unplug the module, measure the throttle drive at contacts 3 and 5 (1.0 to 5.0 ohms) and the supply at contacts 2 and 6 and at contact 2 to earth (at least 4.5 V each). With the control unit disconnected, use the test box to check the wiring for open circuits, shorts to each other and shorts to positive or earth. After renewing the module, clear the fault memory and adapt the control unit to it.

Fits: VW Passat B5 (3B)

• Special tools named: V.A.G 1551, V.A.G 1552, V.A.G 1598/31
• Renewed: engine control unit

Don't miss

• Depress the accelerator slowly when watching display zones 1 and 2 so the two senders can be compared.
• Throttle drive resistance between contacts 3 and 5 must be 1.0 to 5.0 ohms.
• Supply voltage must be at least 4.5 V at contacts 2 and 6 and at contact 2 to earth.
• Keep the engine control unit disconnected while testing wiring with the test box.
• Adapt the engine control unit to the throttle valve module after renewal and clear the fault memory.

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

🔧 Engine codes this applies to

📋 Procedure

1. Connect fault reader V.A.G 1551 (V.A.G 1552). Then switch ignition on and select engine control unit with "“Address word”" 01. (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, 6 and 2 for "“Display group number 62”" and confirm entry with Q key.
4. Check throttle valve angle of sender 1 G187 at idling speed stop in display zone 1.
5. Check throttle valve angle of sender 2 G188 at idling speed stop in display zone 2.

6. Slowly depress accelerator down to full throttle position and observe the angle display in display zones 1 and 2: [Note: The reason why the display in display zone 1 increases and the display in display zone 2 decreases is because the potentiometers (angle senders) in the throttle valve control module run in opposite directions.This means that the voltage tap of one angle sender moves towards 5 V. (The more the throttle valve is opened, the higher the voltage; percentage figure increases).Voltage tap of angle sender 2 decreases from 5 V towards 0 V. (The more the throttle valve is opened, the lower the voltage becomes; percentage figure decreases).]
7. Press → button.
8. Press buttons 0 and 6 for function "“End output”" and confirm entry with Q button.
9. Switch off ignition.
10. Press → button.
11. Press buttons 0 and 6 for function "“End output”" and confirm entry with Q button.
12. Switch off ignition.
13. Pull 6-pin connector from throttle valve module (arrow).
14. Measure resistance of throttle valve drive between contacts 3 + 5; specification: 1.0...5.0 Ω.
15. Renew throttle valve module J338.
16. Read fault memory, if necessary, repair any faults and then clear fault memory , Reading and clearing fault memory.
17. Adapt engine control unit to throttle valve module .
18. Check voltage supply of throttle valve module and lines to control unit .
19. Checking accelerator position sender: Rep. Gr. 20; Electronic engine output control (electronic throttle control); Checking accelerator position sender
20. Renew engine control unit .
21. Pull 6-pin connector from throttle valve module (arrow).
22. Connect multimeter to measure voltage at connector contacts 2 + 6.
23. Switch on ignition. Specification: at least 4.5 V
24. Switch off ignition.
25. Connect the multimeter to measure voltage to contact 2 of the connector and earth.
26. Switch on ignition. Specification: at least 4.5 V
27. Switch off ignition.
28. Connect test box V.A.G 1598/31 to control unit wiring harness. The engine control unit remains disconnected.
29. Check lines between test box and connector for open circuit using current flow diagram:
30. Additionally check wires for short to one another.
31. Additionally check lines for short circuit to battery positive or earth.
32. Check voltage supply of engine control unit .

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