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This article will explain how to carry out the Rodeo Test procedure on Mercedes-Benz vehicles. 

Table of Contents

What is a Mercedes ABC System?

 Mercedes ABC System or Active Body Control System is a computer-controlled hydraulic suspension System that allows a smooth control of the vehicle body motions and thus eliminating body roll in many driving situations. Cornering, accelerating, and braking. 

 What is Rodeo Test Procedure?

It is a test that lets your Mercedes-Benz mimic the movement of a bucking bronco to check the performance of ABC components.

A Mercedes-Benz diagnostic tool will activate the pump to send hydraulic fluid to every suspension struts, continuously adjusting each side of the suspension until each has reached its maximum adjustment.

 The fluid movement will also control the ride height and the damping force. 

 You can expect the air to be flushed out completely after the test.

 This test will also re-calibrate the suspension and leave Benz’s suspension working smoothly after refilling the fluids. 

Although the system would get rid of air over time, you can carry this test or expedite the process using the ride height button to cycle through the levels about fifteen times.


  1. Find the OBD-II port on the left side of the steering wheel at the bottom of the dash. Open the port cover and connect the scanner to the port.connect-scanner
  2. Turn on the ignition.
  3. Turn on your Scanner and choose the car’s model. If using Star Diagnostic C3, C4, C5, open up Xentry and select your chassis. You will need to press F2 a few times to get to the diagnostic menu. 
  4. Choose System Selection.choose-system-selection
  5. Choose Active Body Control. Depending on the scanner, this may be under the Chassis category. 
  6. A prompt will appear, verifying if the ignition is on; if the ignition has been switched on, choose ok. If not, then turn on the ignition first the choose ok at the prompt.choose-ignition-on
  7. Wait until the scanner is able to establish communication with the vehicle. 
  8. Choose Read fault codes; This is a necessary step because some fault codes would prevent the system from executing ABC Tests, such as code descriptions that pertain to 0 working
  9. If there are no pressure-related errors, Press the return symbol to go back to the previous
  10. Choose actuation test.choose-actuation-test
  11. Choose a menu item with the word Rodeo; this will execute a Rodeo
  12. Press ok on the Actuation prompt.choose-ok-rodeo
  13. Press ok on the next confirmation
  14. Turn the engine on to continue with the test.
  15. Verify that the ABC pressure sensor is more than 180 bars and the engine is
  16. Press F3 or Startpress-f3
  17. The vehicle’s suspensions would start rising and falling.suspension-moving
  18. Monitor each suspension's minimum and maximum height; it should be the same for all four sides. If one side did not move or the height is not the same as the others, then there could be an issue with struts for the affected side.
  19. Press-F4 stop to stop the Rodeo Test.stop-rodeo-test
  20. Turn off the ignition.

Warning on performing a Rodeo Test 

  • Although a Rodeo test is beneficial, it should be executed cautiously, since a Rodeo test will subject your suspension system to every possible scenario under load that your suspension system does not normally encounter in everyday driving. This might force weak components to break during the test; a shattered piece of a broken component might get lodged in a valve block, causing sagging issues.

How does the ABC System work?

The System is controlled by an ABC module that monitors inputs from sensors and sends commands to the valve blocks to control the inflow and outflow of hydraulic fluid from the struts, thus keeping the chassis level all the time.

The System detects problems within its components and categorizes errors according to the severity, determined by the color of messages displayed on the dashboard. 

  • Blue or white warnings -The control module detected a problem, but the system is still operational. 
  •  Red warning - The control module detected a severe problem.  Red warnings that stay on the dash -mean the system is not operational. 

Some warnings tend to appear and disappear; this means that the system has some glitch but has returned to normal operation.

Troubleshooting ABC Suspension

See this article for more help on troubleshooting Mercedes-Benz ABC suspension problems.