What actually is the test bench mode / roller mode?

Not all vehicles have a so-called Test stand mode / roller mode. This is a special mode for the test bench performance measurement, but also for that Brake test. For example, if you go with a BMW vehicle X Drive four-wheel drive off, then disabled in some cases, the roll mode all-wheel drive on the front axle. In other words, only the rear axles are still driven. Furthermore, all electronic helpers such as traction control or ESP are complete disabled.

In this mode, a power measurement is usually possible without any problems and it can save automatic controls with regard to drive / power on the part of the vehicle are made. So is a unadulterated test result actionable. In vehicles from BMW, the role mode is often via a secret menu activated. As an example of the BMW F30 335i. With this vehicle, you press the button for resetting the trip meter for a long time and this brings you to the special menu.

further down: BMW, Mercedes & Co. Role mode - that's how it works!

The names also differ depending on the vehicle. Older model series from Mercedes-Benz refer to the option as "Roller test". But the principle is the same. Here too disabled the mode the ESP and the traction control completely. However, the way you get to the menu differs depending on the vehicle. Another example based on a Mercedes C-Class of the W 203 series:

• Radio off
• Set the display to the output menu
• remove key
• Insert the key
• set to level 1
• Press the button 3 times to delete the trip meter / consumption etc.
• a tone sounds
• Stage 2 (ignition)
• Menu is active
• then on "Roller dynamometer ESP - a" place
• the measurement can begin

also for the brake test bench

Activate from Roller dynamometer test is also necessary for many vehicles when driving on a brake test bench. Errors in the control unit are avoided here and the wheel sensors are not affected. Because the brake test on a conventional roller dynamometer that is not suitable for all-wheel drive carries the risk that it will tension comes and possibly also to overuse of the drive train. This is because the braking forces are then transferred, so that the test value can be falsified. One Misdiagnosis in terms of braking performance is the result.

Why is the mode actually necessary?

Mainly it's about Error in the control unit during the brake test and around tension. If you don't activate the mode, you also run the risk of the wheel sensors or the ABS unit becoming defective. One scenario is, for example, that one axle turns and the other does not, the electronics think that the stationary wheels may be locking and the ABS then tries to get this "locking" of the wheels under control by intervening.

Inform the testing organization of the mode

Many testing organizations as well as workshops either do not know the mode, or they are simply “too lazy” to activate it. In the course of the main inspection, the tester should therefore be informed about the dyno mode / roller mode for the brake test to activatein order to obtain a good measurement result and to protect the vehicle technology.

Alternative to the role mode menu

A any Alternatively, if the menu cannot be activated or simply no way into the secret menu is known, you can also drag the corresponding ESP / ASR protection be. Depending on the vehicle, this can lead to various error messages. Some vehicles (especially older ones) can be easily measured in this way. Next it can also be possible that the mode only has a corresponding diagnostic device can be activated.

summary information

Since the various manufacturers of all-wheel drive vehicles also use different concepts for power distribution, no blanket statement determine which vehicle can be measured under which conditions on a roller brake tester not designed for all-wheel drive vehicles. If the vehicle has such a special mode and this is not used, then in most cases the brake tester is switched off or the vehicle is pushed out of the roller set. However, if this does not happen, i.e. the test bench does not switch off, then overload / tension in the drive train can occur, which can result in expensive repairs. Tip: All-wheel drive vehicles should be driven out of the test bench with stationary rollers in order to avoid unnecessary wear and tear.

BMW xDrive G30 5 Series, G20 3 Series, G15 8 Series, X3, X5, F Series & Co.

For many (not all) vehicles, roll mode only works in Sport+ mode

• long press on the trip meter (reset button).
• then press briefly until roll mode is in the middle between the red bars
• then long press to enable roll mode (DSC off)? – appears
• then long press DSC until DSC off appears
• then start the test run

Mercedes W212 W204 W218 C218 test bench mode secret menu / roller test

W205 Mercedes C Class Mopf facelift test bench mode/roller test

Mercedes Viano (W 639) dynamometer mode / roller test

We hope that you have received our information report on the topic / term Role mode (Further designations / keywords are: Drive test, brake test bench mode, brake test mode, power measurement mode, power test bench mode, test bench mode, test bench mode, roller operation, roller test stand mode, roller test) from the Autotuning category.