Renewing Motronic control unit J220: Audi A3 (AXW, BAG, BHD, BLF, …)

🧭 Before you start

Fits: Audi A3 (8P, 2003–2012)

• Renewed: shear bolts

Don't miss

• Connect vehicle diagnostic, testing and information systemVAS 5051B and select vehicle system "“01 - Engine electronics”" from list. When doing this, the ignition must be switched on.
• Always start by displaying the control unit identification and coding and printing it out.
• The wiper shafts will now run to the service position.
• Make sure you fit protective housing back on engine control unit.

🔧 Engine codes this applies to

📋 Procedure

1. Connect vehicle diagnostic, testing and information systemVAS 5051B and select vehicle system "“01 - Engine electronics”" from list. When doing this, the ignition must be switched on.
2. Always start by displaying the control unit identification and coding and printing it out.
3. Switch off ignition.
4. Lever off caps on windscreen wiper arms with a screwdriver.
5. Loosen hexagon nuts (arrow) several turns.

6. Loosen wiper arms from wiper shafts by tilting slightly.
7. Completely remove hexagon nuts and detach wiper arms from wiper shafts.
8. Unclip washer jets (arrow).
9. Push washer jets through assembly opening back into plenum chamber, leaving hoses connected.
10. Pull off rubber seal (1) from plenum chamber cover.
11. Detach plenum chamber cover (2).
12. Release clip “arrow” and remove engine control unit. You can then unplug the connector from the engine control unit.
13. First close bonnet.
14. Switch ignition on and then off again. Within 10 seconds, press wiper switch down once to brief wipe position. [Note: The wiper shafts will now run to the service position.]
15. Then open bonnet again.
16. Remove ignition key.
17. ⚠ The following procedure must be followed exactly to prevent any damage (scorching) to wiring, connectors, insulation and control units. Observe operating instructions for hot air blower. — Select settings on hot air blower as shown in illustration, i.e. set temperature potentiometer (2) to maximum heat output and two-stage air flow switch (3) to position 3. [Note: Then use hot air blower to heat shear bolts. This step reduces inhibiting action of locking fluid on shear bolt threads and makes it easier to unscrew these bolts.Cover up all painted parts to avoid any damage caused by hot air blower or vice-grip pliers.]
18. ⚠ Parts of the protective housing will become very hot as a result of heating the shear bolts. Take care to avoid burns. Try to ensure that only the shear bolt is heated and none of the nearby components. These should be covered if necessary. — Place the hot air blower nozzle close to the shear bolt on the protective housing.
19. Switch on the hot air blower and heat the bolt for approximately 20 to 25 seconds.
20. Then grasp the bolt head with the vice-grip pliers and unscrew the shear bolt.
21. Release front connector (1) from engine control unit and unplug.
22. Pull engine control unit out of retainer (arrow) (wiper shafts in service position).
23. Release rear connector on engine control unit and unplug.
24. Make sure you fit protective housing back on engine control unit.
25. Clean threaded holes for shear bolts to remove any residue from locking fluid. This can be done using a thread tap.
26. Use new shear bolts.
27. Return wiper arms to normal position.
28. First close bonnet.
29. Switch on ignition and press wiper switch down once to brief wipe position. The wipers will then return to the normal position.
30. Activate engine control unit in "“Guided Fault Finding”" under the test procedure / function "“Replace engine control unit”".

Other AUDI procedures

• Removing engine · 41 torque figures
• Removing and installing camshafts – Audi · 18 torque figures
• Checking fuel pressure sender G247 · 19 torque figures
• Installing toothed belt – VW Passat B6 · 17 torque figures
• Removing and installing high-pressure pump – VW Passat B8 · 16 torque figures
• Removing and installing toothed belt – Audi · 56 torque figures
• Removing engine – Audi A8 D3 · 41 torque figures
• Removing camshaft timing chain from camshafts – Audi A6/A7 C7 · 38 torque figures
• Installing engine – Audi A8 D4 · 36 torque figures
• Removing and installing camshaft timing chain · 29 torque figures