Removing and installing onboard supply control unit 2J520 — AUDI
Removing and installing onboard supply control unit 2J520 on Audi: 13 steps. What to remove, in what order, and what to check after.
Workshop procedure for AUDI — the exact step sequence and torque figures, straight from real workshop data.
🧭 Before you start
Fits: Audi Q7 (4L, 2005–2015)
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- The new onboard supply control unit 2J520 must be encoded in "“Guided Fault Finding”" or "“Guided Functions”" mode vehicle diagnostic tester.
📋 Procedure
- When renewing control unit select "“Replacement”" function for appropriate control unit in "“Guided Fault Finding”" or "“Guided Functions”"vehicle diagnostic tester.
- Switch off ignition and take out ignition key.
- Remove front passenger seat 72.
- Open drawer (1) under bracket for front passenger seat.
- Release retaining clips on rear of cover (2) in direction of arrows (A).
- Then remove cover from bracket for front passenger seat in direction of arrow (B).
- Remove bolt (4).
- Unplug electrical connectors (1) and (2).
- Lift frame (3) with control units out of retainers.
- Release clips (arrows) and slide control unit (3) out of frame until it reaches stop. If necessary, release clips again and remove control unit from frame.
- Press retaining clip (2) to side and pull onboard supply control unit 2J520(item 1) out of frame.
- The new onboard supply control unit 2J520 must be encoded in "“Guided Fault Finding”" or "“Guided Functions”" mode vehicle diagnostic tester.
- Install front passenger seat 72.
Other AUDI procedures
- 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
- Removing and installing natural gas tanks 3 and 4
- Checking voltage supply and current consumption of fuel system pressurisation pump G6, engine codes CFHC, CFHE, CFHF, CLCA, CLCB, CFJA
- Emptying fuel tank, front-wheel drive, engine codes CAYD, CAYE, CFHC, CFHF, CLCA, CUUB, CUUC, CUUD, CUUE, CUUF
- Installing cover for gearbox housing and 5th gear
- Removing and installing brake caliper, floating caliper disc brake FN3
Who makes these pages, and how
TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com
The story behind TorqFix →Workshop data on this page last updated 20 Sep 2026.