Volkswagen Golf Service & Repair Manual: Trailer detector control unit -J345-
| The trailer detector control unit -J345- detects a power
consumption of at least 5 W
→ Remark when “towing a trailer” and passes this information
to various control units via the CAN data bus. |
| The trailer detector control unit -J345- receives
information (regulation of lights) from the onboard supply
control unit -J519- and the convenience system central control
unit -J393- via the CAN data bus. |
| 1) |
The turn signal system or the side lights must
be switched on to detect the “trailer”. |
| Information concerning checking the control unit, fault
displays and fault finding is located in the workshop manual
→ Electrical system; Rep. gr.97. |
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| Retrofitting trailer detector control
unit -J345- |
| Retrofitting a trailer detector control unit -J345- is
possible in essence but not easy because it has to be connected
to the CAN data bus of the vehicle. The control unit then has to
be coded with the aid of “Guided fault finding”
→ Vehicle diagnostic tester. |
 Note
| It is recommended that alternative control units available
on the open market and not approved by Volkswagen are avoided
without exception. If equipment of this type is installed, the
guarantee will become void. Generally, these are connected to
the tail lights and not integrated in the electrical system of
the vehicle, which makes far more sense. The consequence is that
faulty diagnoses in the bulb failure warning system or
malfunctions can occur, among other things. Furthermore, dimmed
bulbs (combined brake and tail light) cannot be actuated. |
|
| Coding trailer detector control unit
-J345- |
| Coding is described in
→ Electrical system; Rep. gr.97. |
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The trailer socket must be connected in accordance with the
manufacturer's instructions to the electrical system of the
pulling vehicle.
When i ...
Since higher demands are placed on the engine cooling system
when a trailer is being towed, the cooling system is uprated in
conjunction with factory fitted towing at ...
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Trailer socket
Engine cooling