How to Reverse the Audi Start/Stop Button with VCDS

This tutorial documents how the default behaviour of the Start/Stop button was reversed on a compatible Audi using VCDS.

After the demonstrated modification, the Start/Stop system is switched off when the engine starts. The driver can still enable it manually by pressing the factory Start/Stop button.

This procedure does not physically remove the Start/Stop system.

What reversing the Start/Stop button means

In the standard configuration, the Start/Stop system is normally active after starting the engine. Pressing the button disables it for the current journey.

With the reversed configuration demonstrated here:

• the engine starts with Start/Stop inactive,
• pressing the factory button activates Start/Stop,
• the original system and button remain installed,
• the modification can be reversed by restoring the original adaptation value.

This is different from removing Start/Stop hardware or permanently bypassing the vehicle’s control system.

Compatibility warning

The documented VCDS path is:

09 – Cent. Elect. → Security Access → 20113 → Adaptation → Channel 34

The exact adaptation channel and supported values depend on the Central Electronics module, software version and vehicle configuration.

Continue only when the control module matches the procedure shown in the video. If channel 34 is missing, has a different description or shows an unexpected value, do not enter 0 without obtaining the correct documentation for that controller.

Before changing the adaptation

Prepare:

• a compatible VCDS diagnostic interface,
• a Windows computer with VCDS,
• stable vehicle battery voltage,
• the original adaptation value.

Before making the change:

1. Run and save a complete VCDS Auto-Scan.
2. Record the original value stored in channel 34.
3. Take a screenshot of the adaptation screen.
4. Confirm that there are no relevant Central Electronics faults.
5. Keep the ignition on during the coding procedure.

The original channel value is required if you later want to restore the factory behaviour.

Video: reversing the Start/Stop button

The film shows the original VCDS procedure and the controller configuration on which the change was tested.

Step 1: Connect VCDS

Connect the VCDS interface to the vehicle’s OBD-II port and the computer.

Switch on the ignition and open VCDS. Confirm that the diagnostic interface can communicate with the vehicle.

Do not start changing adaptation values until the original Auto-Scan has been saved.

Step 2: Open Central Electronics

From the VCDS main screen, select:

Select Control Module → 09 – Cent. Elect.

The displayed controller details should match the type of module demonstrated in the video.

Step 3: Enter Security Access

Select:

Security Access – 16

Enter the documented access code:

20113

Confirm the code.

If VCDS rejects Security Access 20113, stop. Do not repeatedly try unrelated access codes. The control module may use a different procedure or may not support this modification.

Step 4: Open adaptation channel 34

Select:

Adaptation – 10

Open:

Channel 34

Read and record the complete original value before changing it.

Do not rely only on memory. Save it in the Auto-Scan notes or take a screenshot.

Step 5: Enter the documented new value

For the compatible controller shown in this tutorial, enter:

New value: 0

Select:

Test

Check whether VCDS accepts the test value and whether the displayed information remains consistent.

Then select:

Save

Confirm the adaptation change when VCDS asks for confirmation.

Value 0 is the result documented in the original procedure. It must not be copied to a controller with a different channel definition or coding layout.

Step 6: Cycle the ignition

After VCDS confirms the saved value:

1. Exit the control module correctly.
2. Switch off the ignition.
3. Wait briefly for the control modules to shut down.
4. Switch the ignition back on.
5. Start the engine.
6. Check the Start/Stop button indicator and system status.

The Start/Stop system should now begin in the reversed state documented in the video.

Step 7: Test the factory button

Press the factory Start/Stop button.

Confirm that:

• the system changes state,
• the button still operates normally,
• no warning appears,
• no new fault is stored.

The modification should reverse the default state, not disable the button.

If channel 34 is missing

Do not create a new channel and do not alter an unrelated adaptation entry.

A missing channel can mean:

• the vehicle uses another Central Electronics module,
• the controller uses named adaptation channels,
• the software version is different,
• the Start/Stop configuration is stored elsewhere,
• this method is not supported.

Use the complete controller identification from the VCDS Auto-Scan to find the correct vehicle-specific procedure.

If value 0 is rejected

Restore the original value if it was changed during testing.

Possible reasons include:

• incompatible controller software,
• incorrect Security Access,
• different channel definition,
• insufficient battery voltage,
• an active diagnostic session problem,
• an unsupported adaptation value.

Do not repeatedly test random values.

If Start/Stop behaviour does not change

Check:

• VCDS reported that the new value was saved,
• the ignition was fully cycled,
• the system was tested after starting the engine,
• the selected channel belongs to the correct module,
• no Start/Stop or energy-management faults are stored,
• the vehicle meets the normal conditions required for Start/Stop operation.

Temperature, battery state, climate-control demand and other operating conditions can affect whether Start/Stop is currently available.

Restore the factory behaviour

To undo the modification:

1. Connect VCDS.
2. Open 09 – Cent. Elect.
3. Enter Security Access 20113 if required.
4. Open Adaptation – 10.
5. Select channel 34.
6. Enter the original value saved before the modification.
7. Select Test and then Save.
8. Cycle the ignition.
9. Test the Start/Stop button.

Do not use a value copied from another vehicle as the factory setting. Restore the value recorded from your own controller.

VCDS coding list

Additional documented VCDS procedures are available here:

Always verify compatibility before applying a coding procedure to a different vehicle or control-module version.

Legal and environmental considerations

Start/Stop forms part of the vehicle’s original emissions and fuel-consumption configuration. Changing its default behaviour may affect compliance with local requirements.

Check the rules applicable to the vehicle before making the modification. The system should remain functional and available through the factory button.