Component Description For Trailer Recognition Control Unit - GF31.19-P-4050GW
Model 463 (except 463.242/342)
as of model year 2013 up to model year 2019
Model 463.342
as of model year 2013
Shown on model 463.23
Location
The trailer recognition control unit is installed on the left-hand side in the trunk.
Tasks
The trailer recognition control unit has the following tasks:
- Reading in of sensors and signals
- Evaluation of input factors
- Trailer recognition
- Actuation of the trailer lighting
- Lamp failure indicator
- Emergency light function
- Consumer shutoff
Reading in of sensors and signals
The input factors are read in via the following connection:
- Interior CAN (CAN B)
Interior CAN
The signals are read in by the trailer recognition control unit via the interior CAN.
The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).
Evaluation of input factors
The input factors are evaluated by the microprocessor and the corresponding components are actuated.
Trailer recognition
The trailer recognition control unit uses current monitoring of the outputs "left taillight", "right taillight", "left turn signal light" and "right turn signal light" to recognize whether the trailer supply line is inserted or not. When one of the two loads is recognized, the supply line is found to be inserted and the trailer is thereby also recognized. This status is sent via the interior CAN.
Actuation of the trailer lighting
The trailer recognition control unit actuates the following trailer components over the trailer socket (X58):
- Taillights and license plate lamp
- Turn signal lamp
- Brake lights, flashing brake lights
- Rear fog light (without code ZU7 (National version for Canada) and without code ZU8 (National version for the USA))
- Backup lamp
Upon requirement of the flashing brake lights, the SAM control unit sends (N10) the time period of the dark phase of the brake lights. The trailer recognition control unit cancels brake light actuation for the duration of this time.
Lamp failure indicator
The trailer recognition control unit monitors the function of the light sources on the trailer. However, only faults in the general lamp path are recognized. If a failure is detected the trailer recognition control unit sends a corresponding signal over the interior CAN.
Trailer lighting in LED version:
For reliable lamp failure recognition, the minimum current for each lamp path must be = 50 mA.
If this minimum current is undershot, a fault message appears in the multifunction display (A1p13) of the instrument cluster (A1), despite the fact that the trailer lighting is functioning correctly (only with LED turn signal lights).
Emergency light function
If the trailer recognition control unit fails or if there is a corresponding request placed via the interior CAN, the trailer's taillights are actuated.
Consumer shutoff
If requested by the SAM control unit, circuit 30 to the trailer socket is switched off.
| Trailer recognition control unit wiring diagram | PE31.19-P-2101-97ZGA |