Removing and installing anti-theft engine control unit J623 (with locking plate) — VW

🧭 Before you start

Fits: VW Passat B6 (3C, 2005–2010)

Don't miss

• The shear-head bolt threads are coated with locking compound. Heating the shear-head bolt with a hot air blower releases the locking effect of the locking compound.

🔧 Engine codes this applies to

📋 Procedure

1. ⚠ For vehicles with heavy duty running gear; vehicle must be restricted to a maximum of 210 km/h via the engine control unit. Drive shafts can be damaged at speeds above 210 km/h. Perform function "“Restricting maximum speed”" in Guided function using Vehicle diagnostic tester. — Switch off ignition.
2. Remove wiper arms Electrical system 92. Windscreen wiper system; Removing and installing wiper arms.
3. Remove plenum chamber cover General body repairs, exterior 64. Flush-bonded windows; Assembly overview - plenum chamber cover. [Note: The shear-head bolt threads are coated with locking compound. Heating the shear-head bolt with a hot air blower releases the locking effect of the locking compound.]
4. ⚠ Cover lines, connections and control units in the vicinity of the engine control unit to prevent damage through heat (scorching/melting of plastics etc.). — Turn temperature setting potentiometer (2) to maximum heat output (600°C).
5. Set two-stage switch for volume of air (3) to position 3.

6. ⚠ When shear-head bolts are heated up, parts of the protective housing will be subjected to a large amount of heat. Wear protective gloves to avoid possible injury. — Place nozzle of hot air blower close to shear-head bolt.
7. Switch on hot air blower and heat the bolts.
8. Unscrew shear-head bolt (2) using pliers on bolt head.
9. Pull connector (1) off heated windscreen control unit J505.
10. Lift cover (1) and pull it forwards.
11. Slide connector locking devices (1) on engine control unit outwards and pull off both connectors.
12. Remove retainer frame with engine control unit from plenum chamber.
13. Press locking device (1) outwards and slide engine control unit (2) from retaining frame.
14. Slide engine control unit (1) into retaining frame in direction of arrow.
15. Fit retainer frame with engine control unit onto retainer in plenum chamber.
16. Fit connectors to engine control unit and slide locking devices (1) inwards.
17. Slide cover (1) over engine control unit and press it downwards.
18. Tighten new shear-head bolts (2) evenly until bolt head shears off.
19. Fit connector (1) to heated windscreen control unit J505.
20. Install plenum chamber cover General body repairs, exterior 64. Flush-bonded windows; Assembly overview - plenum chamber cover.
21. Install wiper arms Electrical system 92. Windscreen wiper system; Removing and installing wiper arms.

Other VW procedures

• Adjusting vacuum unit for turbocharger, engines with code letters AXX, BPY, BWA
• Removing and installing fuel gauge sender 2G169 – Audi A8 D4
• Removing and installing anti-theft engine control unit J623 · 1 torque figures
• Checking fuel pressure and residual pressure (up to high-pressure pump)
• Removing and installing fuel pressure sender G247 · 1 torque figures
• Removing engine · 41 torque figures
• Removing and installing camshaft – VW Golf Cabriolet · 47 torque figures
• Adjusting valve timing – VW Passat B5 · 83 torque figures
• Removing and installing camshafts – VW Passat B6 · 39 torque figures
• Removing and installing coolant pump · 53 torque figures