(Retrofit Trailer Hitch Wiring Harness - AN31.19-P-8100-05LWH)
Model 253.3 up to 5/31/19
| Notice | Notes on retrofitting electrical/optical lines | AH82.00-P-0000-01A | |
| Notice | Notes on the use of paint scraping nuts on ground connections | AH00.19-P-1000-20A | |
| Notice | Information on preventing damage to electronic components due to electrostatic discharge | AH54.00-P-0001-01A | |
| Notes on safety-relevant components | AH00.00-Z-0019-01A |
| Number | Designation | Model 253 (except 253.99) as of model year 2020 | Model 253 (except 253.99) up to model year 2020 | ||
|---|---|---|---|---|---|
| BA00.19-P-1005-01E | Right rear wheel well ground point | W3/8 | Nm | 10 | 10 |
| Number | Designation | Model 253 (except 253.99) as of model year 2020 | Model 253 (except 253.99) up to model year 2020 | ||
|---|---|---|---|---|---|
| BA00.19-P-1016-01E | Left front footwell ground point | W15/5 | Nm | 10 | 10 |
| Number | Designation | Model 253 (except 253.99) as of model year 2020 | Model 253 (except 253.99) up to model year 2020 | ||
|---|---|---|---|---|---|
| BA00.19-P-1017-01E | Left front footwell ground point (CAN) | W15/6 | Nm | 10 | 10 |
| Number | Designation | Model 253 (except 253.99) as of model year 2020 | Model 253 (except 253.99) up to model year 2020 | ||
|---|---|---|---|---|---|
| BA00.19-P-1028-01E | Left footwell ground point | W34 | Nm | 10 | 10 |
Connection scheme
Routing diagram, shown on model 253.9
- Connect black 24-pin connector (20.1) of trailer hitch wiring harness (20) to trailer recognition control unit (N28/1).
The black 24-pin connector (20.1) was routed into the vehicle interior during installation of the trailer hitch crossmember.
- Connect white 6-pin connector of trailer hitch wiring harness (20) to the white 6-pin connector of control unit wiring harness (22).
- Use retaining clip to fasten electrical connection for vehicle interior/trailer hitch (X58/33) onto rear center section.
- Connect black 6-pin connector (22.2) to trailer recognition control unit (N28/1).
- Connect black 10-pin connector (22.3) to trailer recognition control unit (N28/1).
- Route control unit wiring harness (22) along the existing lines to the rear fuse and relay module and secure using cable ties.
- Fit brown fuse holder (22.1) onto rear fuse and relay module (K40/5) and check fuse assignment.
Contact cavity 1 = 25 A
Contact cavity 2 = 15 A
Contact cavity 3 = 25 A
Contact cavity 4 = 30 A
Contact cavity 5 = 15 A
The brown fuse holder contact cavities (22.1) are labeled.
- Route white 4-pin connector (22.5) to rear SAM control unit (N10/8) and connect.
- Route brown/white line (BN/WH) of control unit wiring harness (22) to rear right wheel arch ground point (W3/8) and connect
.
- Route front footwell branch-off line (22.4) along existing lines to the B-pillar and fix in place using cable ties.
- Route red/blue line (rt/bl) of front footwell branch-off line (22.4) to right A-pillar fuse box (F1/3), as shown in the cable duct, and fix in place using cable ties.
- Route front footwell branch-off line (22.4) in the driver footwell, as shown in the cable duct, and fix in place using cable ties.
- Remove violet multiple fuse carrier (80) from fuse box on right A-pillar (F1/3).
- Install red/blue line (RD/BU) into contact cavity8 of the violet multiple fuse carrier (80) of fuse box on right A-pillar (F1/3).
- Install violet multiple fuse carrier (80) into fuse box on right A-pillar (F1/3).
- Insert a fuse with a fuse rating of 30 A into contact cavity of the violet multiple fuse holder (80).
- Connect brown line (BN) of front footwell branch-off line (22.4) to front left footwell ground point (W15/5)
If more than 5 round cable lugs are connected,
↓
Left front footwell ground point (CAN) (W15/6)
- Route green 4-pin coupling of front footwell branch-off line (22.4) to driver-side A-pillar and fix in place using cable ties.