Lower Multifunction Steering Wheel Button Group Electric Controller Unit, Component Description - GF82.90-P-4007RFM

WARNING: This page is about a different car, the 2023 Mercedes-Benz GLC300, 2022 Mercedes-Benz GLC300, 2021 Mercedes-Benz GLC300, 2020 Mercedes-Benz GLC350e, and 2020 Mercedes-Benz GLC300. However, it is still accessible from the selected car via links, so may be relevant.

Model 205 as of model year 2019 with code U88 (AMG steering wheel buttons (AMG DRIVE UNIT))

Model 253 as of model year 2020 with code U88 (AMG steering wheel buttons (AMG DRIVE UNIT))

Shown on left-hand drive vehicle

Fig 1: Lower Multifunction Steering Wheel Button Group Electric Controller Unit Components Location - Model 253 As Of Model Year 2020 With Code U88

Courtesy of MERCEDES-BENZ USA

Location

The electric controller unit for the lower multifunction steering wheel button group is attached to the lower steering column.

Tasks

The electric controller unit for the lower multifunction steering wheel button group is used for communication between the lower multifunction steering wheel button group 1 (S163/3) or the lower multifunction steering wheel button group 2 (S163/4) and the drive program control unit (N145). The electric controller unit for the lower multifunction steering wheel button group is responsible for the following individual tasks:

CAN interface:
- Receiving control data for the lower multifunction steering wheel button group from the drive program control unit over the steering column tube module control unit (N80) and the steering wheel CAN (CAN LR)
- Forwarding of operation signals of lower multifunction steering wheel button group over the steering wheel CAN and the steering column tube module control unit to the drive program control unit
Direct line (serial peripheral interface):
- Reception of operation signals from lower multifunction steering wheel button groups
- Actuation of displays in lower multifunction steering wheel button groups

The lower multifunction steering wheel button groups can be used, e.g. to make settings in the following areas: ESP®, suspension, transmission, engine start/stop, exhaust gas flap actuation and drive program.