How to reset assyst plus in Mercedes Benz?

This blog will explain the procedure to reset the Assyst plus in Mercedes Benz and answer the following questions: when to reset Assyst plus? Can you reset Assyst plus without the Xentry scanner? What is the function of the Assyst plus?

How to reset Assyst plus in Mercedes Benz?

The procedure to reset Assyst plus in Mercedes Benz is as follows:

• Unlock the vehicle and connect the Xentry OBD-II scanner.
• Turn on the ignition and select the instrument cluster control unit.
• Open the actuation tab and select reset general maintenance.
• After selection, Assyst plus will reset the service data and show the next service interval.
• Disconnect the OBD-II scanner and turn off the ignition.

It is possible to use other OBD-II scanners but they should have the ability to perform control unit programming. Read-only scanners cannot reset the Assyst plus. If the service interval is incorrect in the instrument cluster, the Assyst plus can be re-initialized by performing a software update.

Depending on the vehicle, the Assyst plus function is present in the instrument cluster or the powertrain control unit. Therefore, it can also be reset using the workshop menu in the instrument cluster.

The workshop menu is locked, a workshop technician opens it to check the actual level of engine oil and the battery voltage. The option to reset the Assyst plus is given under the service menu. It will be reset after selecting the confirmed service.

When to reset Assyst plus?

The reset of Assyst plus is only performed after the scheduled vehicle maintenance is carried out. Assyst plus will continue to show the service due message in the instrument cluster until it is not reset.

Mercedes Benz has two types of service, the minor service is called service A, and the major service is called service B. Service A is followed by service and the interval between the two services is 10,000 miles or 1 year, whichever is earlier.

All the oil change data records are stored in the Assyst plus system. A workshop code is generated by Assyst plus and it is used to determine the service scope for the vehicle. The service checksheet is printed out according to the workshop code generated by the Assyst plus system.

The Assyst plus system also must be reset when the control unit is replaced. In the Mercedes Benz vehicles manufactured before 2012, the Assyst plus system was found in the central gateway.

Mercedes Benz in the models manufactured after 2013 integrated the central gateway into the instrument cluster or the front signal acquisition and actuation control unit. The Assyst plus data became even more advanced and it is possible to save the oil data records.

Can you reset Assyst plus without the Xentry scanner?

Yes, it is possible to reset the Assyst plus without the Xentry or any other OBD-II scanner. The procedure is as follows:

• Insert the key into the ignition, switch to position ‘1’, and ensure that the mileage is displayed in the multi-function display in the instrument cluster.
• Place both hands on the steering wheel and press the ‘call’ and ‘Ok’ buttons simultaneously for 5 seconds. An alternate method is to press the call button first and within the 1-second press and hold the ok button.
• Release both buttons and scroll to the workshop menu option. If the option is not visible after the service menu then repeat the above step.
• Press the down arrow and select the Assyst plus menu. Press OK and go into the service data where all the previous service data is displayed.
• Press the down arrow repeatedly until the confirm service option comes on the screen. Confirm with the OK button
• ‘Is the service carried out’ message appears in the instrument cluster. Press OK to confirm.

If the Assyst plus will reset if the process is completed successfully and it will display the next service interval in the service menu. This process cannot be undone, hence only resetting the Assyst plus system after the service is completed.

The key combination to unlock the workshop menu depends on the type of steering wheel and the number of buttons. On the latest cars, there are capacitor buttons that require the OK button to be held for more than 10 seconds.

There are no changes in the process to reset the Assyst plus, confirm service options are always present in the service data. If the confirmation of service is failed then the distance between the previous service and the current service is too less.

The previous service record must be deleted if the confirmation of the service cannot be performed from the workshop menu in the instrument cluster. A Xentry scanner or an OBD-II scanner is required to delete the data records in the Assyst plus system.

What is the function of the Assyst plus?

The function of the Assyst plus is to calculate the remaining distance and time for the service of the vehicle. It also saves the data related to the total service performed on the vehicle. Assyst stands for Active service system plus.

The service reminder message starts to appear in the multi-function display of the instrument cluster. If the vehicle has the Mercedes Me connect app, it will also show a notification with the remaining distance of time.

Customers can also book a service appointment using the Mercedes Me connect app at the nearest authorized dealership. If the service is not performed, the message changes to ‘service exceeded by days or miles’ whichever is less.

It also indicates the type of service due, if it is service A the following tasks are carried out on the vehicle.

• Engine oil and oil filter replacement
• AC filter check or replacement (depending on the contamination level)
• All fluid level check
• Vehicle interior and exterior inspection
• Service indicator reset

In service B all the above-mentioned operations are carried out along with the following additional tasks:

• Transmission fluid replacement
• Spark plugs replacement  (for gasoline engines)
• Diesel filter replacement (for diesel engines)

A vehicle health card is also given to the customer, it contains important information like the condition of brakes and tires. The battery voltage and the test report printed out from the midtronics battery tester are also attached to the vehicle health card.

Conclusion

This blog explained the procedure to reset the Assyst plus in Mercedes Benz. It can be reset with or without an OBD II scanner. The service history is also saved at authorized service centers so it is easy to determine if the service is carried out at a local workshop or at an authorized workshop. Mercedes Benz can reject warranty claims if service is overdue by more than 500 miles.