How to Check Oil on Audi A4 with VCDS

This guide provides a comprehensive walkthrough on how to check and change your Audi A4’s automatic transmission fluid (ATF) using VCDS (Vag-Com Diagnostic System). This process, often shrouded in ambiguity online, requires specific steps within the VAG software that are crucial for accurate ATF levels. This guide clarifies the entire procedure, replicating the official Erwin factory steps.

Draining the ATF

Warning: The system is under pressure.

Prerequisites:

• Battery charger/maintainer connected
• Ignition ON, Engine OFF
• Gear selector in Park (Transmission NOT in Emergency Running mode)
• Parking brake engaged
• HVAC, lights, radio OFF
• Vehicle on a level surface

Procedure:

1. Connect VCDS and select [02 – Auto Trans].

2. Go to [Adaptation – 10].

3. Select [Draining Oil Pressure Reservoir] from the dropdown menu (Channel 1B).

4. Change [Stored Value] from OFF to [New Value] “Activate” using [Do it!]. Then [Go Back].

5. Navigate to [Adv. Meas. Values] and select these for display:

   • “Oil pressure reservoir: status of emptying”
   • “Oil pressure reservoir: pressure – Data” (optional)
   • “Electrical pump 2 for trans. oil: actual speed” (optional)
   • “Oil pressure reservoir: status” (optional)

6. Observe “status of emptying” for the value “Leeren aktiv” (Empty active) or similar indication.

7. Once complete, the value should change to “Druckspeicher entleert/ATF-Motor gesperrt” (Pressure accumulator emptied/ATF motor disabled) or similar.

8. Select [Done, Go Back], then [Close Controller, Go Back – 06]. Turn the ignition OFF.

9. Disconnect the battery charger. The ATF pump is now disabled, the accumulator drained, and the vehicle must not be driven. A “P187E – Oil Pressure Reservoir, No Pressure” fault code may be stored. The mechatronic unit can now be removed for service.

10. Following the official factory repair manual, drain the ATF oil (typically using a T60 Torx), ensuring complete drainage. Replace the drain plug.

Filling the ATF

Important: Overfilling can mix ATF and manual transmission fluid (MTF), causing irreversible transmission damage. Check and note the MTF level beforehand for any signs of mixing (high level).

Procedure:

1. With the ignition OFF and following the factory manual, remove the fill/control plug (often a T30 Torx M10x1.0) and drain plug. Measure the drained ATF.
2. Refill with ONLY Audi-approved G 055 529 A2 ATF. The maximum fill volume is approximately 3.5 liters. Temporarily replace the cleaned fill plug.

Turning the Auxiliary Pump Back On

Procedure:

1. Connect the battery charger and ensure all electricals are off.
2. Turn the ignition ON, engine OFF (only after adding ATF).
3. In VCDS, go to [02 – Auto Trans], then [Adaptation – 10].
4. Select [Oil pressure reservoir emptying] and set [New Value] to “OFF” using [Do it!]. [Go Back].
5. In [Adv. Meas. Values], confirm “Oil pressure reservoir: status of emptying” shows [Not active].
6. Select [Done, Go Back], then [Close Controller, Go Back – 06]. Turn the ignition OFF for 30 seconds.

Checking the ATF Level

Prerequisites:

• Confirm in VCDS that [02 – Auto Trans] -> [Adaptation – 10] -> [Oil pressure reservoir emptying] is set to OFF.
• Gear selector in Park
• Parking brake engaged
• HVAC, lights, radio OFF
• Vehicle on a level surface

Procedure:

1. Start the engine and let it idle.

2. Monitor the “Transmission fluid temperature” in [Adv. Meas. Values].

3. When the ATF temperature reaches 35°C:

   • Activate the ATF motor: In [Adaptation – 10], select [ATF_motor_speed_requirement – Activation] and set [New Value] to “Vorgabe Aktiv” (Default active) using [Do it!].
   • Run the pump at 3000 RPM for 20 seconds: In [Adaptation – 10], select [ATF_motor_speed_requirement – Motor Speed Requirement] and set [New Value] to “3000” using [Do it!].
   • Run the pump at 600 RPM for 90 seconds: In [Adaptation – 10], select [ATF_motor_speed_requirement – Motor Speed Requirement] and set [New Value] to “600” using [Do it!].

4. When the ATF level is correct, a small amount of fluid will flow out of the fill hole.

5. Insert the fill plug.

6. Shut down the ATF pump: In [Adaptation – 10], select [ATF_motor_speed_requirement – Activation] and set [New Value] to “keine Vorgab” (no default) using [Do it!].

7. Select [Done, Go Back], then [Close Controller, Go Back – 06]. Turn the ignition OFF for 30 seconds.

8. Stop the engine. Turn the ignition ON (all electricals should be off). Check and clear any fault codes.

9. Road test the vehicle and check for leaks and fault codes.

This detailed process ensures accurate ATF levels in your Audi A4, contributing to optimal transmission performance and longevity. Using VCDS allows for precise control over the ATF pump and monitoring of key parameters, resulting in a professional-grade fluid change.