Checking angle senders for throttle valve drive: Audi A3 (AJK, ARE, ARX, ARY, …)

🧭 Before you start

Fits: Audi A3 (8L, 1996–2003)

• Special tools named: V.A.G 1598/31

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• Connect up the vehicle diagnostic and service information systemVAS 5052 and select the engine electronics control unit. When doing this, the ignition must be switched on.
• The engine control unit converts the voltage values of the angle senders into a percentage referenced to 5 V and displays these percentage values (5 V supply voltage corresponds to 100 %).
• Connect the test box V.A.G 1598/31 to the wiring harness to the engine control unit, but do not connect the actual engine control unit .

🔧 Engine codes this applies to

📋 Procedure

1. Connect up the vehicle diagnostic and service information systemVAS 5052 and select the engine electronics control unit. When doing this, the ignition must be switched on.
2. Select the function "“Read measured value block”".
3. Select "“Display group number 062”".
4. Check the specifications for the electronic throttle potentiometer voltages in display zones 1 and 2. [Note: The engine control unit converts the voltage values of the angle senders into a percentage referenced to 5 V and displays these percentage values (5 V supply voltage corresponds to 100 %).]
5. Observe display zones 1 and 2.

6. Slowly floor the accelerator pedal. [Note: The reason for the display in zone 1 increasing whereas the display in zone 2 decreases is the opposing action of the potentiometers (angle senders) in the throttle valve module.This means that the voltage tapped at one of the angle senders approaches 5 V (the further the throttle valve is opened, the higher the voltage becomes and the percentage indicated increases).The trend of the voltage tapped at angle sender 2 is away from 5 V and towards 0 V (the further the throttle valve is opened, the lower the voltage becomes and the percentage indicated decreases).]
7. Check voltage supply and wiring to throttle valve module. Pay particular attention to the possibility of loose or corroded connectors.
8. Check the accelerator pedal position senders .
9. Unplug the connector from the throttle valve module J338.
10. Switch on ignition.
11. Connect up the multimeter (voltage measuring range) as follows:
12. Check wiring between engine control unit and throttle valve module J338.
13. Unplug the connector from the throttle valve module J338.
14. Connect the test box V.A.G 1598/31 to the wiring harness to the engine control unit, but do not connect the actual engine control unit .
15. Check for open circuit and short to earth or positive in the following wiring:
16. Eliminate open circuit in wiring/short circuit if necessary.
17. Replace the throttle valve module J338.

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