Replacing engine electronics control unit: Audi 1.9 TDI (1Z, AHU)

AHU
Fitting location => Exploded view of fitting locations - Page 23-4

Special tools and workshop equipment required

VAS 5051 with VAS 5051/1 and VAS 5051/2

or

V.A.G 1551 with V.A.G 1551/1

Removing

Connect vehicle diagnostic, testing and information system VAS 5051 or fault reader V.A.G 1551 and select engine electronics control unit with "address word" 01 => Page 01-2.
Ignition must be on.

028906021GC 1.9l R4 EDC
G00SG
1408 ⇒
Code 00005
WSC 12345
Fault reader V.A.G 1551 displays control unit identification (example).

Always start by displaying control unit identification and printing it out => Page 01-4.

Switch off ignition.

Slit floor covering as shown -arrows- and fold it back.

Pull off condensate hose -arrow- on vehicles with air conditioner.

Insert screwdriver next to retainer between control-unit mounting plate and plastic slot.
Turn screwdriver if necessary to disengage retainer tabs at mounting plate above retainer from plastic slot recess.
Pull down control unit slightly and remove screwdriver.
Pull down control unit 3 ... 4 cm. In this position, control unit engages in a second recess (service position).
Disconnect control-unit plug after releasing clip.

Notes:

Always switch off ignition before disconnecting or connecting engine control unit connector.
In service position, test box V.A.G 1598/18 can be connected for measurement and test purposes to engine wiring harness.

To release control unit, pull open clip and disconnect control-unit plug.

Note:

The following operations are only necessary if the control unit is to be completely removed.

Unfasten catch as described and carefully pull control unit downwards out of slot.
To remove control unit on vehicles with air conditioner, carefully press detached condensate drain hose aside so that side flange of control unit does not damage drain hose.

Installing

Notes:

Always switch off ignition before disconnecting or connecting engine control unit connector.

On vehicles with air conditioner, check whether condensate drain hose -arrow- has been connected before installing cover beneath glove box.

If necessary, encode control unit => Page 01-54.
Adapt engine electronics control unit to immobilizer control unit.

=> Electrical System; Repair Group 01; Self-diagnosis; Adaption on replacement of engine control unit
Electrical System
Self-diagnosis
Adaption on replacement of engine control unit

Vehicles with cruise control system:

Activate cruise control system
=> Page 23-101.