Audi A4/B7 RHD Electrical System for Towing Hitch

Read the installation manual prior to starting work.
The electrical kit should only be installed by qualified personnel.
Follow guidance in the current repair manual when carrying out installation work on the vehicle.
Caution – Disconnect the battery!
Danger of damage to the vehicle’s electronic system. Data which are stored electronically may get lost.
Read out the fault storage prior to starting work.
Note
During installation special attention has to be paid to the following points:
• Cables must not be pinched or damaged.
• All sealing elements have to be installed properly.
• The socket gasket has to be positioned on the insulating sleeve and not on the individual wires.
• Lay the cables such that they do not rub on the vehicle and are not bent.
• Do not lay any cables near the exhaust system.

Failure of a trailer light (also direction indicator lamps, but not back-up light or rear fog lamp) is indicated by the light failure monitoring system on the combination instrument. There is no additional indicator light (C2) for monitoring the direction indicators on the trailer in the vehicle.
When a trailer is used, the rear fog lamp of the traction vehicle is deactivated.
In the case of trailers without rear fog lamp, a rear fog lamp has to be retrofitted.
A socket adapter may only be used in conjunction with a trailer. When the trailer is no longer used, remove the socket adapter.
Correct trailer operation has to be checked using a trailer or a test instrument with load resistors.
Subject to technical alterations!

Install electrical kit
1. Disconnect battery.
2. Remove the following covers and panelling, as necessary:
• In the boot
- Boot floor cover
- Loading sill cover
- Left side panel
• Along the right hand side of the vehicle
- Side panel rear (Cabrio)
- Scuff plates, driver's side
- Right panelling by the steering column
- Fuse box cover
3. Remove the cover from the 40 mm hole in the floor panel, below the left tail light (Fig. 1/5).
Note
In vehicles with tyre pressure check: remove the 4-pin plug from the tyre pressure monitoring unit at the back right on the bumper. Unlock the black outer housing on this plug, open the green secondary lock and unclip the three cables. Remove the hole grommet 4B0 971 908 from this cable loom. On the towing hitch cable set, expose the second opening of the hole grommet 4B0 971 908, feed the cable set for the tyre pressure check and seal it correctly.
Re-assemble the 4-pin plug in the reverse order.
Chamber 1 = br/bl, chamber 2 = ye/bl, chamber 3 = gn/pu.
4. Route the end of the cable with the 14-pin and 6-pin plugs from outside through the hole to the equipment rack (Fig. 1/4).
5. Insert the rubber grommet in the hole (fig. 1/5).
6. Route the end of the cable set with the socket to the socket mounting plate (fig. 1/7).
7. Secure the socket cable set (in vehicles with a tyre pressure monitoring function, secure the cable set for the tyre pressure monitoring unit as well) between the tail end panel and the towing hitch on the bumper carrier with plug-in fixing cable ties.
Fit socket
8. Push contact insert into the socket housing and slide rubber seal up to the socket.
9. Secure the socket to the mounting plate with the screws provided (Fig. 1/7), torque setting: max. 2.0 Nm.. If necessary shorten screws.

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