Reset Mercedes-Benz Oil Service Reminder

Mercedes-Benz GLA-Class (X156) Oil Service Reminder Reset

ByRushit Hila, PE, ASE Certified Updated onOct 18, 2026

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Rushit Hila

PE, ASE Certified

Rushit Hila is the founder of YOUCANIC and a passionate advocate for empowering car owners through knowledge. With a background in automotive diagnostics and years of hands-on repair experience, Rushit leads the YOUCANIC team in creating practical, easy-to-follow guides and tools that help drivers fix their own vehicles. His mission is simple: make car repair less intimidating and more accessible for everyone.

Does your Mercedes-Benz’s oil service reminder flash and need to be reset after changing the engine oil? This guide provides step-by-step procedures for resetting the oil life service reminder on the GLA250 and X156 Mercedes-Benz year models from 2013 to 2021.

At a Glance

Reset steps: key to the accessory position, open the service menu on the cluster with the steering wheel buttons, select ASSYST PLUS, then confirm the full service.
Do not start the engine during the reset.
Service A covers oil and filter, fluid checks, tire pressures and a brake inspection. Service B adds more, including the cabin filter and brake fluid.
Use oil with the right MB approval, such as 229.5 on many gasoline models.
Only reset after the work is done. The reset does not record any service.

Procedure

If your car has a push start button, pull the button out of the ignition switch so you can insert the key.
Insert the key into the ignition switch and turn it one click to the accessory position. Do not start the engine.
Set the instrument cluster to display the miles.
Press the phone button on the right side of the steering wheel, then promptly press the OK button on the left side. Hold them both for a few seconds.
The vehicle’s instrument cluster will show different menus. Select ASSYST PLUS and press the OK button to confirm.
Select the Full-Service Menu on the vehicle’s instrument cluster.
Scroll down by pressing the down arrow and select Conf. Full Service by pressing the ok button.
Select the oil grade used in the vehicle.
The instrument cluster will ask, “Oil Grade Service carried out?” Select YES, and press OK to confirm the oil reminder reset.

This tutorial shows how to reset the service overdue reminder on a Mercedes-Benz GLA-Class X156.

Reset the reminder only after the service is done

Worth stating plainly: this procedure resets a counter. It does not change the oil, and it does not inspect anything. The ASSYST system on a Mercedes also keeps a record of when each service was carried out, and that record is what a dealer or a buyer looks at when assessing the car’s history. Resetting it without doing the work leaves a service logged against the vehicle that never happened, which devalues the car and hides how overdue it actually is.

Understand Service A and Service B

Mercedes alternates between two service types, and the reminder tells you which one is due. Service A is the lighter of the two and covers the engine oil and filter, fluid level checks, a tire inflation check, a brake component inspection and a reset of the counter. Service B covers everything in Service A and adds the cabin air filter, the brake fluid change and a more thorough inspection.

The two alternate, so a car that has just had Service A will be due Service B next time. The gap between them is not a fixed mileage. ASSYST PLUS calculates the remaining interval from how the car is actually driven, counting cold starts, short journeys, engine load and the time elapsed, which is why two identical cars can show very different distances remaining.

Use the right oil specification

Mercedes approves oils against its own sheet numbers rather than by viscosity alone, and the correct approval for your engine is listed in the owner’s manual and usually printed on the oil filler cap. Gasoline models of this generation commonly call for an oil carrying MB approval 229.5 or 229.51, and the lower ash 229.51 and 229.52 specifications matter on cars fitted with a particulate filter. Buying a 5W-30 that does not carry the right approval number is a false economy on an engine of this kind.

If the reset does not take

A few things commonly go wrong. The sequence usually needs the ignition switched on with the engine not running, and starting the engine partway through will abandon it. The menu path differs between the earlier and later instrument clusters fitted across this model run, so if your display does not match the steps above, look for the service menu under the vehicle or maintenance submenu instead.

On some variants and on cars where the counter has already gone past due, the reset has to be performed with diagnostic software rather than through the steering wheel buttons. A full system scanner that supports Mercedes can carry out the service reset directly and will also read any stored codes, which is useful if a warning message appeared alongside the service reminder.

If the reminder returns within a few hundred miles of a successful reset, the counter is being recalculated from a stored fault rather than from the service record. Read the codes before resetting it a second time.

Frequently Asked Questions

Does resetting the GLA service reminder mean the service is done?

No. Resetting only restarts the countdown. Reset it after the oil and filter have actually been changed.

What is the difference between Service A and Service B?

Service A is a basic oil and filter service with inspections. Service B adds more checks and items such as the cabin filter and brake fluid when due.

Can I reset the GLA reminder without a scan tool?

Yes, on most cars the reminder can be reset from the instrument cluster menu using the steering wheel buttons, as shown above.

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