Overview
This document contains information on:
General
Function requirements
Function
General
When checking the vehicle, the electric parking brake and the brake and traction system can be set to roller test mode.
Roller test mode deactivates ESP®, ABS and ASR.
Function requirements
Front wheels stationary and rear wheels turning slowly (brake test stand)
Service brake is braked
Engine in operation
Transmission in position N
Function
Roller test mode prevents the wheels from locking up when checking or adjusting the brake system. Roller test mode allows different rotational speeds on the individual wheels or axles.
If the vehicle is on the brake test stand and the rollers of the brake test stand are activated, the ESP® control unit automatically recognizes the rpm difference between the rear wheels and the front wheels and switches to roller test mode.
As a result, no faults are detected by the ESP® control unit when testing on the brake test stand and no fault messages are displayed.
If roller test mode is activated, the following displays light up in the instrument cluster:
Electronic Stability Program warning indicator
Anti-lock braking system indicator lamp