Removing and installing trailer detector control unit J345 — VW
Removing and installing trailer detector control unit J345 on VW: 12 steps, 4 torque figures. What to remove, what to tighten and to how many Nm, what to.
Workshop procedure for VW — the exact step sequence and torque figures, straight from real workshop data.
🧭 Before you start
Fits: VW Golf VII Variant (BA)
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- Following installation, a new trailer detector control unit J345 must be encoded .
🔩 Torque settings
Values can differ between engine variants — check the code stamped on your block.
| Torque | Fastener / step |
|---|---|
| 2 Nm (1.5 lb-ft) | On installation, tighten securing bolts (2) |
| 2 Nm (1.5 lb-ft) | Remove securing bolts (2 |
| 3.5 Nm (2.6 lb-ft) | Tighten securing bolts |
| 5 Nm (3.7 lb-ft) | Tighten securing bolts |
ℹ️ Always cross-check the exact figure against your vehicle's factory manual before final tightening — a wrong torque can damage the engine. These values are extracted from workshop data and may not cover every variant or revision.
📋 Procedure
- Switch off ignition and all electrical consumers.
- If fitted, disengage ignition key out in position 0 (forward notch).
- Remove cover in luggage compartment side trim.
- Remove vehicle tool kit.
- Undo and remove bolts (1).
- Pull mounting for vehicle tool kit in direction of arrow (A).
- Disconnect connectors (2).
- Remove mounting for vehicle tool kit from side panel in direction of arrow (B).
- Press fastener (1) in direction of arrow (A).
- Lift trailer detector control unit J345(2), and remove it in direction of arrow (B). [Note: Following installation, a new trailer detector control unit J345 must be encoded .]
- Connecting vehicle diagnostic tester
- Coding trailer detector control unit J345.
Other VW procedures
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- Removing and installing alternator, 1.9 l TDI engine
- Removing and installing moulded headliner, Passat CC 2009► and CC 2010► · 1 torque figures
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.