Mechatronic unit, removing and installing

WARNING: This page is about a different car, the 2010 Audi A8, 2009 Audi A8, 2008 Audi A8, 2007 Audi A8, and 2004 Audi A8. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Always replace mechatronics unit if it is dirty or defective.
General repair notes → General Repair Notes .
Rules of cleanliness for working on automatic transmissions → Rules of cleanliness for working on automatic transmissions .

Removing

CAUTION: Observe procedures for disconnecting battery → 27 - BATTERY, STARTER, GENERATOR, CRUISE CONTROL .

Switch ignition off.

Fig 1: Right Luggage Compartment Side Trim

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Remove cover of luggage compartment right side trim - arrows -.

Fig 2: Battery Cover

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Remove cover - 1 - from above battery.

NOTE:

Disregard - 2 -.

Fig 3: Ground (GND) Battery Lead

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Disconnect Ground (GND) lead - arrow - at the battery.
Remove oil pan → Oil pan, removing and installing .
Remove oil screen → Oil strainer, removing and installing .

Fig 4: Transmission Electrical Connector

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Disconnect electrical connector - 2 - on transmission by turning screw connections counter-clockwise.

NOTE:

Disregard - 1 -.

Touch vehicle ground with hand (without gloves) to discharge static.

CAUTION:

Always discharge static by touching a grounded object, e.g. vehicle ground, before touching or removing mechatronics unit.
Never touch contacts in 16-pin connector, as the static charge could destroy the control module and thus the mechatronics unit.

Fig 5: Wiring Harness Connector Securing Clip

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Remove wiring harness connector securing clip - arrow - on outside of transmission housing.

Fig 6: Removing/Installing Securing Bolts For Mechatronics Unit In Sequence

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Remove Mechatronic bolts in - 11 to 1 - sequence.

NOTE:

Only bolts marked with - 1 to 11 - may be loosened.
If other bolts are loosened, this may affect the function of the mechatronics unit or it may come apart.

Remove mechatronics unit together with wiring harness from transmission, at the same time guiding out connector for wiring harness.

Installing

Fig 7: Removing/Installing Oil Seal For ATF Strainer From Transmission

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Make sure that the seal - B - is properly installed and secured.
Replace wiring harness connector O-rings and lightly coat with ATF.

Fig 8: Locating Wiring Harness With Connector Is Attached To Mechatronics Unit

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Clip wiring harness - A - onto mechatronics unit - B -. At the same time, insert the tab - arrow - on backside of wiring harness into mechatronics unit.

NOTE:

If the tab on the backside of the wiring harness breaks off, the wiring harness must be replaced → Wiring harness in transmission, removing and installing .

Insert wiring harness connector into transmission housing.

Installation position: Flat part of rear collar faces downward; tabs on collar are horizontal.

Fig 9: Inserting Transmission Selector Lever Stud Into Groove On Selector Slide

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Set mechatronics unit in place without using force, and at the same time insert stud of selector lever - arrow - into groove of selector slide - A - ; if necessary, move selector slide back or forth.

Fig 10: Removing/Installing Securing Bolts For Mechatronics Unit In Sequence

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Tighten bolts - 1 - and - 2 - for mechatronics unit to 2 Nm.
Then tighten bolts to 8 Nm in specified sequence - 1 to 11 -.

Fig 11: Wiring Harness Connector Securing Clip

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Connect securing clamp - arrow - on wiring harness connector.
Install oil strainer → Oil strainer, removing and installing .
Install oil pan → Oil pan, removing and installing .
Connect battery → 27 - BATTERY, STARTER, GENERATOR, CRUISE CONTROL .

Fill with ATF → ATF, draining and filling after repairs .